Respiratory apparatus

ABSTRACT

A mask apparatus for a respiratory treatment can permit delivery of breathable gas to a user. In one example, the mask may employ a frame and cushion to form a seal for both mouth and nose. The frame may be adapted for coupling with a respiratory treatment apparatus so as to permit communication of a pressurized gas from the respiratory treatment apparatus. The cushion, which may be foam, may have a substantially under the nose configuration or over the nose configuration. The mask may have a common plenum chamber for both nose and mouth. The cushion may further define a centrally open lip superior region. The cushion may be adapted to couple with the frame directly or to the frame in conjunction with a cushion support clip. Various features of the cushion may further promote sealing and comfort for the under the nose design.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/137,649, filed Sep. 21, 2018, which is a continuation of U.S. patentapplication Ser. No. 14/765,492, filed Aug. 3, 2015, now U.S. Pat. No.10,188,820, which is a national phase entry under 35 U.S.C. § 371 ofInternational Application PCT/AU2014/000077 filed Feb. 4, 2014,published in English, which claims priority from Australian ProvisionalPatent Application Nos. 2013900349 filed Feb. 4, 2013 and 2013900348filed Feb. 4, 2013, all of which are incorporated herein by reference.

BACKGROUND OF THE TECHNOLOGY 2.1 Field of the Technology

The present technology relates to one or more of the detection,diagnosis, treatment, prevention and amelioration of respiratory-relateddisorders. In particular, the present technology relates to medicaldevices or apparatus, and their use. Such devices may include aninterface for directing a treatment to a patient respiratory system.

2.2 Description of the Related Art

The respiratory system of the body facilitates gas exchange. The noseand mouth form the entrance to the airways of a patient.

The airways consist of a series of branching tubes, which becomenarrower, shorter and more numerous as they penetrate deeper into thelung. The prime function of the lung is gas exchange, allowing oxygen tomove from the air into the venous blood and carbon dioxide to move out.The trachea divides into right and left main bronchi, which furtherdivide eventually into terminal bronchioles. The bronchi make up theconducting airways, and do not take part in gas exchange. Furtherdivisions of the airways lead to the respiratory bronchioles, andeventually to the alveoli. The alveolated region of the lung is wherethe gas exchange takes place, and is referred to as the respiratoryzone. See “Respiratory Physiology”, by John B. West, Lippincott Williams& Wilkins, 9th edition published 2011.

A range of respiratory disorders exist.

Obstructive Sleep Apnoea (OSA), a form of Sleep Disordered Breathing(SDB), is characterized by occlusion of the upper air passage duringsleep. It results from a combination of an abnormally small upper airwayand the normal loss of muscle tone in the region of the tongue, softpalate and posterior oropharyngeal wall during sleep. The conditioncauses the affected patient to stop breathing for periods typically of30 to 120 seconds duration, sometimes 200 to 300 times per night. Itoften causes excessive daytime somnolence, and it may causecardiovascular disease and brain damage. The syndrome is a commondisorder, particularly in middle aged overweight males, although aperson affected may have no awareness of the problem. See U.S. Pat. No.4,944,310 (Sullivan).

Cheyne-Stokes Respiration (CSR) is a disorder of a patient's respiratorycontroller in which there are rhythmic alternating periods of waxing andwaning ventilation, causing repetitive de-oxygenation and re-oxygenationof the arterial blood. It is possible that CSR is harmful because of therepetitive hypoxia. In some patients CSR is associated with repetitivearousal from sleep, which causes severe sleep disruption, increasedsympathetic activity, and increased afterload. See U.S. Pat. No.6,532,959 (Berthon-Jones).

Obesity Hyperventilation Syndrome (OHS) is defined as the combination ofsevere obesity and awake chronic hypercapnia, in the absence of otherknown causes for hypoventilation. Symptoms include dyspnea, morningheadache and excessive daytime sleepiness.

Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a groupof lower airway diseases that have certain characteristics in common.These include increased resistance to air movement, extended expiratoryphase of respiration, and loss of the normal elasticity of the lung.Examples of COPD are emphysema and chronic bronchitis. COPD is caused bychronic tobacco smoking (primary risk factor), occupational exposures,air pollution and genetic factors. Symptoms include: dyspnoea onexertion, chronic cough and sputum production.

Neuromuscular Disease (NMD) may encompass many diseases and ailmentsthat impair the functioning of the muscles either directly via intrinsicmuscle pathology, or indirectly via nerve pathology. Some NMD patientsare characterised by progressive muscular impairment leading to loss ofambulation, being wheelchair-bound, swallowing difficulties, respiratorymuscle weakness and, eventually, death from respiratory failure.Neuromuscular disorders can be divided into rapidly progressive andslowly progressive: (i) Rapidly progressive disorders: Characterised bymuscle impairment that worsens over months and results in death within afew years (e.g. Amyotrophic lateral sclerosis (ALS) and Duchennemuscular dystrophy (DMD) in teenagers); (ii) Variable or slowlyprogressive disorders: Characterised by muscle impairment that worsensover years and only mildly reduces life expectancy (e.g. Limb girdle,Facioscapulohumeral and Myotonic muscular dystrophy). Symptoms ofrespiratory failure in NMD include: increasing generalised weakness,dysphagia, dyspnoea on exertion and at rest, fatigue, sleepiness,morning headache, and difficulties with concentration and mood changes.

Chest wall disorders are a group of thoracic deformities that result ininefficient coupling between the respiratory muscles and the thoraciccage. The disorders are usually characterised by a restrictive defectand share the potential of long term hypercapnic respiratory failure.Scoliosis and/or kyphoscoliosis may cause severe respiratory failure.Symptoms of respiratory failure include: dyspnoea on exertion,peripheral oedema, orthopnoea, repeated chest infections, morningheadaches, fatigue, poor sleep quality and loss of appetite.

Otherwise healthy individuals may take advantage of systems and devicesto prevent respiratory disorders from arising.

2.2.1 Therapy

Nasal Continuous Positive Airway Pressure (CPAP) therapy has been usedto treat Obstructive Sleep Apnea (OSA). The hypothesis is thatcontinuous positive airway pressure acts as a pneumatic splint and mayprevent upper airway occlusion by pushing the soft palate and tongueforward and away from the posterior oropharyngeal wall.

Non-invasive ventilation (NIV) provides ventilator support to a patientthrough the upper airways to assist the patient in taking a full breathand/or maintain adequate oxygen levels in the body by doing some or allof the work of breathing. The ventilator support is provided via apatient interface. NIV has been used to treat CSR, OHS, COPD, MD andChest Wall disorders.

Invasive ventilation (IV) provides ventilatory support to patients thatare no longer able to effectively breathe themselves and is providedusing a tracheostomy tube.

Ventilators may control the timing and pressure of breaths pumped intothe patient and monitor the breaths taken by the patient. The methods ofcontrol and monitoring patients typically include volume-cycled andpressure-cycled methods. The volume-cycled methods may include amongothers, Pressure-Regulated Volume Control (PRVC), Volume Ventilation(VV), and Volume Controlled Continuous Mandatory Ventilation (VC-CMV)techniques. The pressure-cycled methods may involve, among others,Assist Control (AC), Synchronized Intermittent Mandatory Ventilation(SIMV), Controlled Mechanical Ventilation (CMV), Pressure SupportVentilation (PSV), Continuous Positive Airway Pressure (CPAP), orPositive End Expiratory Pressure (PEEP) techniques.

2.2.2 Systems

One known device used for treating sleep disordered breathing is the S9Sleep Therapy System, manufactured by ResMed. Ventilators such as theResMed Stellar™ Series of Adult and Paediatric Ventilators may providesupport for invasive and non-invasive non-dependent ventilation for arange of patients for treating a number of conditions such as but notlimited to NMD, OHS and COPD.

The ResMed Elisée™ 150 ventilator and ResMed VS III™ ventilator mayprovide support for invasive and non-invasive dependent ventilationsuitable for adult or paediatric patients for treating a number ofconditions. These ventilators provide volumetric and barometricventilation modes with a single or double limb circuit.

A system may comprise a PAP Device/ventilator, an air circuit, ahumidifier, a patient interface, and data management.

2.2.3 Patient Interface

A patient interface may be used to interface respiratory equipment toits user, for example by providing a flow of breathable gas. The flow ofbreathable gas may be provided via a mask to the nose and/or mouth, atube to the mouth or a tracheostomy tube to the trachea of the user.Depending upon the therapy to be applied, the patient interface may forma seal, e.g. with a face region of the patient, to facilitate thedelivery of gas at a pressure at sufficient variance with ambientpressure to effect therapy, e.g. a positive pressure of about 10 cmH2O.For other forms of therapy, such as the delivery of oxygen, the patientinterface may not include a seal sufficient to facilitate delivery tothe airways of a supply of gas at a positive pressure of about 10 cmH2O.

The design of a patient interface presents a number of challenges. Theface has a complex three-dimensional shape. The size and shape of nosesvaries considerably between individuals. Since the head includes bone,cartilage and soft tissue, different regions of the face responddifferently to mechanical forces. The jaw or mandible may move relativeto other bones of the skull. The whole head may move during the courseof a period of respiratory therapy.

As a consequence of these challenges, some masks suffer from being oneor more of obtrusive, aesthetically undesirable, costly, poorly fitting,difficult to use, and uncomfortable especially when worn for longperiods of time or when a patient is unfamiliar with a system. Forexample, masks designed solely for aviators, mask designed as part ofpersonal protection equipment (e.g. filter masks), SCUBA masks, or forthe administration of anaesthetics may be tolerable for their originalapplication, but nevertheless be undesirably uncomfortable to be wornfor extended periods of time, e.g. several hours. This is even more soif the mask is to be worn during sleep. An uncomfortable mask may impacton patient compliance.

Nasal CPAP therapy is highly effective to treat certain respiratorydisorders, provided patients comply with therapy. If a mask isuncomfortable, or difficult to use a patient may not comply withtherapy. Since it is often recommended that a patient regularly washtheir mask, if a mask is not easily replaceable or difficult to clean(e.g. difficult to assemble or disassemble), patients may not replace orclean their mask and this may impact on patient compliance.

For these reasons, masks for delivery of nasal CPAP during sleep form adistinct field.

2.2.3.1 Seal-Forming Portion

Patient interfaces may include a seal-forming portion.

A patient interface may be partly characterised according to the designintent of where the seal-forming portion is to engage with the face inuse. In one form of patient interface, a seal-forming portion maycomprise two sub-portions to engage with respective left and rightnares. In one form of patient interface, a seal-forming portion maycomprise a single element that surrounds both nares in use. Such singleelement may be designed to for example overlay an upper lip region and anasal bridge region of a face. In one form of patient interface aseal-forming portion may comprise an element that surrounds a mouthregion in use, e.g. by forming a seal on a lower lip region of a face.In one form of patient interface, a seal-forming portion may comprise asingle element that surrounds both nares and a mouth region in use.These different types of patient interfaces may be known by a variety ofnames by their manufacturer including nasal masks, full-face masks,nasal pillows, nasal puffs and oro-nasal masks.

One type of seal-forming portion extends around the periphery of thepatient interface, and is intended to seal against the user's face whenforce is applied to the patient interface with the seal-forming portionin confronting engagement with the user's face. The seal-forming portionmay consist of an air or fluid filled cushion, or a moulded or formedsurface of a resilient seal element made of an elastomer such as arubber. With this type of seal-forming portion, if the fit is notadequate, there will be gaps between the seal-forming portion and theface, and additional force will be required to force the patientinterface against the face in order to achieve a seal.

Another type of seal-forming portion incorporates a flap seal of thinmaterial so positioned about the periphery of the mask so as to providea self-sealing action against the face of the user when positivepressure is applied within the mask. Like the previous style of sealforming portion, if the match between the face and the mask is not good,additional force may be required to effect a seal, or the mask may leak.Furthermore, if the shape of the seal-forming portion does not matchthat of the patient, it may crease or buckle in use, giving rise toleaks.

Another type of seal-forming portion may comprise a friction-fitelement, e.g. for insertion into a naris.

Another form of seal-forming portion may use adhesive to effect a seal.Some patients may find it inconvenient to constantly apply and remove anadhesive to their face.

A range of patient interface seal-forming portion technologies aredisclosed in the following patent applications, assigned to ResMedLimited: WO 1998/004,310; WO 2006/074,513; WO 2010/135,785.

2.2.3.2 Positioning and Stabilising

A seal-forming portion of a patient interface used for positive airpressure therapy is subject to the corresponding force of the airpressure to disrupt a seal. Thus a variety of techniques have been usedto position the seal-forming portion, and to maintain it in sealingrelation with the appropriate portion of the face.

One technique is the use of adhesives. See for example US Patentpublication US 2010/0000534.

Another technique is the use of one or more straps and stabilisingharnesses. Many such harnesses suffer from being one or more ofill-fitting, bulky, uncomfortable and awkward to use.

2.2.3.3 Vent Technologies

Some forms of patient interface systems may include a vent to allow thewashout of exhaled carbon dioxide. Many such vents are noisy. Others mayblock in use and provide insufficient washout. Some vents may bedisruptive of the sleep of a bed-partner 1100 of the patient 1000, e.g.through noise or focussed airflow.

ResMed Limited has developed a number of improved mask venttechnologies. See WO 1998/034,665; WO 2000/078,381; U.S. Pat. No.6,581,594; US Patent Application; US 2009/0050156; US Patent Application2009/0044808.

Table of noise of prior masks (ISO 17510-2:2007, 10 cmH₂O pressure at 1m) A-weighted A-weighted sound power sound pressure level dBA dBA YearMask name Mask type (uncertainty) (uncertainty) (approx.) Glue-on (*)nasal 50.9 42.9 1981 ResCare standard (*) nasal 31.5 23.5 1993 ResMedMirage (*) nasal 29.5 21.5 1998 ResMed UltraMirage nasal 36 (3) 28 (3)2000 ResMed Mirage Activa nasal 32 (3) 24 (3) 2002 ResMed Mirage Micronasal 30 (3) 22 (3) 2008 ResMed Mirage SoftGel nasal 29 (3) 22 (3) 2008ResMed Mirage FX nasal 26 (3) 18 (3) 2010 ResMed Mirage Swift (*) nasalpillows 37 29 2004 ResMed Mirage Swift II nasal pillows 28 (3) 20 (3)2005 ResMed Mirage Swift LT nasal pillows 25 (3) 17 (3) 2008 ResMedMirage series I, II (*) full face 31.7 23.7 2000 ResMed UltraMirage fullface 35 (3) 27 (3) 2004 ResMed Mirage Quattro full face 26 (3) 18 (3)2006 ResMed Mirage Quattro FX full face 27 (3) 19 (3) 2008 (*onespecimen only, measured using test method specified in IS03744 in CPAPmode at 10 cm H₂O)

Sound pressure values of a variety of objects are listed belowA-weighted sound Object pressure dB(A) Notes Vacuum cleaner: Nilfisk 68ISO3744 at 1 m Walter Broadly Litter Hog: distance B+ GradeConversational speech 60 1 m distance Average home 50 Quiet library 40Quiet bedroom at night 30 Background in TV studio 20

2.2.3.4 Nasal Pillow Technologies

One form of nasal pillow is found in the Adam Circuit manufactured byPuritan Bennett. Another nasal pillow, or nasal puff is the subject ofU.S. Pat. No. 4,782,832 (Trimble et al.), assigned to Puritan-BennettCorporation.

ResMed Limited has manufactured the following products that incorporatenasal pillows: SWIFT nasal pillows mask, SWIFT II nasal pillows mask,SWIFT LT nasal pillows mask, SWIFT FX nasal pillows mask and LIBERTYfull-face mask. The following patent applications, assigned to ResMedLimited, describe nasal pillows masks: International Patent ApplicationWO2004/073,778 (describing amongst other things aspects of ResMed SWIFTnasal pillows), U.S. Patent Application 2009/0044808 (describing amongstother things aspects of ResMed SWIFT LT nasal pillows); InternationalPatent Applications WO 2005/063,328 and WO 2006/130,903 (describingamongst other things aspects of ResMed LIBERTY full-face mask);International Patent Application WO 2009/052,560 (describing amongstother things aspects of ResMed SWIFT FX nasal pillows).

2.2.4 Respiratory Apparatus (PAP Device/Ventilator)

Examples of respiratory apparatuses include ResMed's S9 AutoSet™ PAPdevice and ResMed's Stellar™ 150 ventilator. PAP devices or ventilatorstypically comprise a flow generator, such as a motor-driven blower or acompressed gas reservoir, and are configured to provide a controlledsupply of breathable gases (e.g., air) to the airway of a patient. Insome cases, the flow of air or other breathable gases may be supplied tothe airway of the patient at positive pressure may be supplied to theairway of a patient by a PAP device such as a motor-driven blower. Theoutlet of the blower PAP device or the ventilator is connected via aflexible delivery conduit an air circuit to a patient interface such asthose described above.

Ventilators or PAP devices typically include a flow generator, an inletfilter, a patient interface, an air circuit delivery conduit connectingthe flow generator to the patient interface, various sensors and amicroprocessor-based controller. The patient interface may include amask or a tracheostomy tube as described above. The flow generator mayinclude a servo-controlled motor, volute and an impeller that forms ablower. In some cases a brake for the motor may be implemented to morerapidly reduce the speed of the blower so as to overcome the inertia ofthe motor and impeller. The braking can permit the blower to morerapidly achieve a lower pressure condition in time for synchronizationwith expiration despite the inertia. In some cases the flow generatormay also include a valve capable of discharging generated air toatmosphere as a means for altering the pressure delivered to the patientas an alternative to motor speed control. The sensors measure, amongstother things, motor speed, mass flow rate and outlet pressure, such aswith a pressure transducer or the like. The apparatus may optionallyinclude a humidifier and/or heater elements in the path of the airdelivery circuit. The controller may include data storage capacity withor without integrated data retrieval and display functions.

BRIEF SUMMARY OF THE TECHNOLOGY

The present technology is directed towards providing medical devicesused in the diagnosis, amelioration, treatment, or prevention ofrespiratory disorders having one or more of improved comfort, cost,efficacy, ease of use and manufacturability.

An aspect of the present technology relates to apparatus used in thetreatment or prevention of a respiratory disorder.

Another aspect of the present technology may relate to methods used inthe treatment or prevention of a respiratory disorder.

One form of the present technology involves an interface that directs atreatment, such as a positive pressure breathable gas, to a patientrespiratory system.

Another aspect of one form of the present technology involves such aninterface that directs a treatment to the nares of the patientrespiratory system.

Another aspect of one form of the present technology is such aninterface that directs a treatment to the nares and mouth of the patientrespiratory system but maintaining a minimal facial contact profile soas to avoid contact or coverage of a majority of a nose of patient.

Another aspect of one form of the present technology is a patientinterface that is moulded or otherwise constructed with a clearlydefined perimeter shape which is intended to match the face profile ofan intended wearer.

Another aspect of some forms of the present technology is a patientinterface that employs a foam cushion. The foam may optionally be partof a cushion assembly that may further implement a flexible supportclip. In some such cases, the flexible support clip can be configuredwith dimensions and material properties so as to both support the foamcushion and complement the foam cushion's compliance. Thus, a relativelythin foam cushion may provide compliance to account for the fine detailson the user's face, while the flexible clip can account for the morecoarse aspects of the facial structure. Such configuration may reducethe amount of foam required for a comfortable and efficient sealing ofthe mask. The reduced amount of foam may minimise the overall size ofthe mask, make it less obtrusive and improve its aesthetic appeal.

Another aspect of some forms of the present technology is a patientinterface that is implemented as a mouth and nose mask with asubstantially above the nose or under the nose seal configuration.

For example, a mask apparatus for a respiratory treatment may include aframe adapted to couple with a respiratory treatment apparatus so as topermit communication of a pressurized gas to a respiratory system of apatient from the respiratory treatment apparatus; and it may include acushion adapted to couple with the frame, the cushion configured as asubstantially under nose seal portion and a mouth seal portion, theunder nose seal portion comprising a sub-nasal ridge formed as asemi-peripheral sealing boundary about both nares of the patient.

In some cases, the cushion may comprise a triangular ring having acommon nasal and mouth aperture. The cushion may be foam. The cushionand the frame may form a common plenum chamber for sealing about thenares and mouth. The cushion may include a protrusion configured to plyadjacent to a nasal ala of the patient. The cushion may include left andright nasal ala protrusions.

In some versions, the mask apparatus may further include a cushionsupport clip configured to couple with the cushion and couple with theframe. The cushion support clip may include first and second opposingsides, wherein the clip is configured to couple with the cushion on thefirst opposing side and to couple with the frame on the second opposingside. The cushion support clip may include a nasal plateau region and amouth periphery region. The nasal plateau region may be approximatelyperpendicular to the mouth periphery region.

The cushion support clip may include a bend region between the nasalplateau region and the mouth periphery region. The bend region may forman approximately nasolabial angle between the nasal plateau region andthe mouth periphery region. The bend region may include a set ofinwardly directing nasal protrusions. The nasal protrusions may beflexible.

In some versions, the cushion support clip may include first and secondcushion support portions, the first and second cushion support portionsmay be configured to provide different flexibility characteristics. Thefirst cushion support portion may be a nasal support region and thesecond cushion support portion may be a lateral mouth support region.The first cushion support portion may have a higher rigiditycharacteristic with respect to the second cushion support portion.Optionally, the sub-nasal ridge includes a scalloped edge. In somecases, the cushion comprises a generally flat sealing surface. Thecushion may include a generally curved sealing surface.

In some cases, such mask apparatus may further include a respiratorytreatment apparatus configured to generate a controlled supply ofbreathable gas at a pressure above atmospheric pressure, the respiratorytreatment apparatus including a gas delivery conduit coupled with theframe to direct the breathable gas to the frame.

In some versions of the mask apparatus, a cushion support clip may beflexible. The cushion support clip may be inwardly concave. The cushionsupport clip may be made of a material other than or different fromfoam. The cushion may be foam externally attached to a flexible clip. Insome cases, a foam surface of the cushion may be configured for directcontact with a patient's skin. A foam of the cushion may be a semi-opencell foam with limited permeability.

Some versions of the present technology may include a respiratory maskfor delivering a respiratory gas treatment. The mask may include a frameand cushion. The cushion may be adapted to couple with the frame. Thecushion may be configured as a substantially under nose seal portion anda mouth seal portion. The cushion may further define a centrally openlip superior region.

The cushion may include a nasal plateau region and a mouth peripheryregion. The cushion may be configured with an approximately nasolabialangle between the nasal plateau region and the mouth periphery region.The cushion may be a triangular ring having a common nasal and mouthaperture. The cushion may be foam.

The cushion and the frame may form a common plenum chamber for sealingabout nares and mouth. The centrally open lip superior region may bewithin the plenum chamber. The cushion may include a protrusionconfigured to ply adjacent to a nasal ala of a patient. The cushion mayinclude left and right nasal ala protrusions.

The respiratory mask may include a clip to removably couple the cushionto the frame. The clip may include flexible nasal protrusions. The clipmay include first and second cushion support portions, the first andsecond cushion support portions being configured to provide differentflexibility characteristics.

In some versions of the present technology, such as when a mask isconfigured for sealing with the mouth and over the nasal bridge, a foamcushion may be implemented.

For example, a foam cushion assembly can be configured to seal aroundthe mouth and over the nasal bridge, and can achieve a comfortable andeffective seal. Such an assembly may include a foam cushion portion, aflexible clip portion and a rigid clip portion. The flexible clip may bearranged to complement the compliance of the cushion so as to allow areduction in the size of the cushion. Whilst the rigid clip portion isgenerally expected to be made of generally hard material, the term“rigid” is relative with respect to the softer “flexible” clip portion(also referred to a soft clip or flexible clip). Thus the rigid portion(also referred to a rigid clip) may have some level of flexibility. Itshardness, however, should be sufficient to facilitate attachment to theframe or to the headgear.

In terms of comfort, the force applied to the user's face at the sealinterface from headgear and treatment pressure of a respiratorytreatment can be distributed over a larger surface area compared totraditional silicone based seals, resulting in better comfort as well asan improved perceived comfort. This may have a positive effect onpatient therapy acceptance and, hence, compliance.

Any mask leak can be dispersed over a wider area resulting in a moredispersed flow, which minimise “jetting” that is attributable toconventional silicone cushions. This is likely to improve patientengagement with therapy and compliance verses that associated withtypical silicone sealing technology.

Some potential benefits of such a foam cushion or assembly may include:

A breathable foam cushion assembly can serve as a cooler skin contactregion and reduce discomfort in sealing areas.

The inclusion of an optional flexible clip allows a reduced overalldimension in the foam component of the cushion, compared to a foam maskwithout such a component. This increases stability without a compromisein comfort and sealing.

A foam cushion assembly can be relatively small in size, unobtrusive,yet easily removable for cleaning and replacement.

Some versions of the present technology include a foam cushion assemblyfor a patient interface. The foam cushion assembly may be adapted tocouple with a patient interface frame. The cushion assembly may includea substantially above nose seal portion and a mouth seal portion. Such acushion assembly may include a foam cushion arranged to form with theframe a common plenum chamber and for sealing about the nose and mouthof the patient, and it may include a cushion support clip arranged tocouple to the foam cushion, wherein the cushion support clip may becharacterised by a height to thickness ratio of at least 3, around anentire periphery of the cushion.

The cushion support clip may be flexible. The flexible cushion supportclip may be formed by a rigid material and the flexibility may beinduced by way of introducing one or more compliance regions. Thecompliance regions may be formed by introducing a line of weakness or aregion of weakness.

The cushion support clip may have an inwardly concave shape, dimensionsand material properties that, when pressure is applied to the patientinterface, facilitate an air spring effect. The cushion support clip maybe made of a material other than foam and silicone. The foam cushion maybe externally attached to the cushion support clip. A foam surface ofthe cushion may be configured for direct contact with a patient's skin.

The foam cushion may be a semi-open cell foam with limited permeability.The foam cushion may have a permeability characteristic in a range ofabout 0 to 20 litters per minute. The foam cushion may have anindentation hardness characteristic in a range of about 110.48 to 303.11Newtons. The foam cushion may have a compression stress straincharacteristic in a range of about 2.32 to 7.26 kilo-pascals. The foamcushion may have an apparent density characteristic in a range of about24.3 to 117.85 kilograms per meter cubed. The foam cushion may have acompression set characteristic in a range of about 0.16 to 17.30percent.

The cushion support clip may be L, C and/or Z-shaped. The cushionsupport clip may include a foam cushion coupling portion, providing acontact surface to which the cushion is attached, a flexible supportportion and a base portion for attaching to a second support clip or tothe frame. The foam cushion assembly may have shape, dimensions andmaterial characteristics of the cushion support clip selected so that atleast a portion of the clip acts as a cantilever spring.

The cushion assembly may also include a second support clip configuredto couple with the cushion support clip and the frame. The secondsupport clip may be more rigid than the cushion support clip and thecushion support clip may be more rigid than the foam cushion. The foamcushion and the cushion support clip may be integrally connected. Thefoam cushion, the cushion support clip and the second support clip maybe integrally connected.

The foam cushion assembly may be configured so that different levels ofsupport and compliance are provided in at least some sections along aperiphery of the cushion assembly. In some versions, one or moreparameters vary in at least some sections of a periphery of the clip,the parameters may include: spring constant of the clip and/or the foamcushion; cross-sectional profile of the clip and/or the foam cushion;wall thickness of the clip; angle of a contact surface of the clip towhich the cushion is attached; overhang of the cushion with respect tothe supporting contact surface; and foam thickness.

The foam cushion assembly may further include a protrusion beingconfigured to be, when in use, depressed by a headgear strap so as toapply pressure on a respective region of the foam cushion.

Some versions of the present technology may include a patient interfaceapparatus for a respiratory treatment. The patient interface apparatusmay include a frame adapted to couple with a respiratory treatmentapparatus so as to permit communication of a pressurized gas to arespiratory system of a patient from the respiratory treatmentapparatus. It may further include a cushion assembly adapted to couplewith the frame of any of the versions described herein.

Some versions of the present technology may include a mask cushionassembly for a patient interface of a respiratory treatment apparatus.The mask cushion assembly may include a peripheral foam cushion adaptedas a seal for a mouth portion. The peripheral foam cushion may befurther adapted as a seal for a nasal portion. The cushion assembly mayfurther include a flexible support component peripherally engaged withthe foam cushion and a rigid support component coupled with the flexiblesupport component, wherein the flexible support component is formed ofan air impermeable material. The flexible support component may beformed of a flexible material.

The flexible support component may be formed by a rigid material,wherein the flexible support component comprises one or more complianceregions inducing flexibility. The compliance regions may be formed byintroducing a line of weakness or a region of weakness.

The rigid support component may include a mask frame. The rigid supportcomponent may include a clip for coupling with a mask frame. The clipmay include at least one snap element. The flexible support componentmay include an internal periphery of a plenum chamber of the maskcushion assembly, the internal periphery adapted to respond to atreatment pressure provided at the mask to increase a sealing force of aseal of the foam cushion.

The flexible support component may include an internal periphery of aplenum chamber of the mask cushion, wherein the flexible supportcomponent is configured to respond with different reaction forces in atleast some regions of the periphery. The regions with different reactionforces may include a side of nose region and a side of mouth region. Theflexible support component may be configured to provide differentroll-in responses in different regions of the periphery of the flexiblesupport component. The different regions may include an upper cheekregion and a side of mouth region. The internal periphery may be formedwith different angles in the different regions, each angle formed by asupport portion and a foam cushion coupling portion. The flexiblesupport component may include one or more of a ‘C’ cross sectionalgeometry and an ‘L’ cross sectional geometry.

The foam cushion coupling portion may include a peripheral lip to whichthe foam cushion may be mounted. In some cases, the engagement of theperipheral lip and foam cushion form an overhang foam portion in atleast some sections along the periphery of the lip. The foam cushion mayinclude a nasal bridge contact region. The nasal bridge contact regionof the foam cushion may include a nasal recess.

The foam cushion may include a substantially under nose seal portion,the under nose seal portion comprising a sub-nasal ridge formed as asemi-peripheral sealing boundary about both nares of the patient.

In some versions, the flexible support component may include a shell ofa plenum chamber and a connection port for coupling to an air circuit ofa respiratory treatment apparatus, and the rigid support component mayinclude a headgear frame including a shell aperture configured forfitting about the shell.

In some versions, a flexible skirt member of a mask component moves toengage and cover an inner surface of the foam cushion, the flexibleskirt member may be air impermeable.

In some versions, a peripheral foam cushion may be generally planar andthe flexible support component and/or the rigid support component mayimpart a three dimensional (3D) contour to the peripheral foam cushion,when attached to the foam cushion. The foam may be a polyurethanesemi-open cell foam of limited permeability.

In some cases, a spring constant of a foam cushion with a nasal recessand flexible support component in a mouth region may be greater than aspring constant of the foam cushion and flexible support component in anasal bridge region. Optionally, a spring constant of the foam cushionand flexible support component in a cheek region may be similar to thespring constant of the nasal bridge region. A spring constant of aflexible clip only configuration in a mouth region may be larger than aspring constant in a cheek bone region and the spring constant in thecheek bone region may be larger than a spring constant in a nasal bridgeregion.

The foam cushion may have a compression stress strain characteristic ina range of about 2.32 to 7.26 kilopascals. The foam cushion may have acoefficient of friction characteristic in a range of about 1.86 to 19.12CF. The foam cushion may have an elongation at break characteristic in arange of about 72.3 to 369.05 percent. The foam cushion may have apermeability characteristic in a range of about 0 to 20 liters perminute. The foam cushion may have an indentation hardness characteristicin a range of about 110.48 to 303.11 Newtons. The foam cushion may havea compression stress strain characteristic in a range of about 2.32 to7.26 kilo-pascals. The foam cushion may have an apparent densitycharacteristic in a range of about 24.3 to 117.85 kilograms per metercubed. The foam cushion may have a compression set characteristic in arange of about 0.16 to 17.30 percent. The foam cushion may have atensile strength characteristic in a range of about 0.03 to 0.27MegaPascals.

The flexible support component may be inwardly concave. The flexiblesupport component may be made of a material other than foam. The cushionmay be made of foam and be externally attached to flexible supportcomponent. A foam surface of the cushion may be configured for directcontact with a patient's skin. One or more parameters may vary in atleast some sections of the periphery of the flexible support component,the parameters may include: spring constant of the flexible supportcomponent and/or the foam cushion; cross-sectional profile of theflexible support component and/or the foam cushion; wall thickness ofthe flexible support component; angle of a contact surface of theflexible support component to which the cushion is attached; overhang ofthe cushion with respect to the supporting contact surface; and/or foamthickness.

Some versions of the mask cushion assembly may further include aprotrusion configured to be, when in use, depressed by a headgear strapso as to apply pressure on a respective region of the foam cushion.

Some versions of the present technology may include a mask cushion for amask frame that may include a foam cushion. The mask cushion may includea peripheral portion adapted as a seal for a mouth portion. Theperipheral portion may be further adapted as a seal for a nasal portion.The foam cushion may further include a stretchable engagement skirt,whereby the foam cushion may be configured as a slip-over foam cover fora supporting structure.

Some versions of the present technology may include a mask cushionassembly for a mask frame. The assembly may include a foam cushion, thefoam cushion may include a peripheral portion adapted as a seal for amouth portion. The peripheral portion may be further adapted as a sealfor a nasal portion. The mask cushion assembly may further include aninner peripheral clip and outer peripheral clip. The clips may beconfigured to engage with a foam support component. The inner peripheralclip may engage on an inner side of the foam cushion and the outerperipheral clip may engage on an outer side of the foam cushion. Theclips may clamp the foam cushion to secure the foam cushion to the foamsupport component. The clips may be configured to clamp the foam so asto round a patient contact surface of the foam cushion. The clips mayfurther include an over-clip portion configured to depress over a topside portion of the foam cushion. The foam cushion may further include aslit to receive an over-clip portion.

Of course, portions of the aspects may form sub-aspects of the presenttechnology. Also, various ones of the sub-aspects and/or aspects may becombined in various manners and also constitute additional aspects orsub-aspects of the present technology.

Other features of the technology will be apparent from consideration ofthe information contained in the following detailed description,abstract, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present technology is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings, in whichlike reference numerals refer to similar elements including:

4.1 Treatment Systems

FIG. 1a shows components of a system suitable for use with examples ofthe present technology. A patient 1000 wearing a patient interface 3000,such as nasal prongs only covering the patient's nose, receives a supplyof air at positive pressure from a PAP device 4000. Air from the PAPdevice is humidified in a humidifier 5000, and passes along an aircircuit 4170 to the patient 1000;

FIG. 1b shows a PAP device 4000 in use on a patient with a nasal masktype of patient interface;

FIG. 1c shows a PAP device in use on a patient with a full-face masktype of patient interface;

4.2 Therapy 4.2.1 Respiratory System

FIG. 2a shows an overview of a human respiratory system including thenasal and oral cavities, the larynx, vocal folds, oesophagus, trachea,bronchus, lung, alveolar sacs, heart and diaphragm;

FIG. 2b shows a view of a human upper airway including the nasal cavity,nasal bone, lateral nasal cartilage, greater alar cartilage, nostril,lip superior, lip inferior, larynx, hard palate, soft palate,oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea;

4.2.2 Facial Anatomy

FIG. 2c is a front view of a face with several features of surfaceanatomy identified including the lip superior, upper vermillion, lowervermillion, lip inferior, mouth width, endocanthion, a nasal ala,nasolabial sulcus and cheilion;

FIG. 2d is a side view of a head with several features of surfaceanatomy identified including glabella, sellion, pronasale, subnasale,lip superior, lip inferior, supramenton, nasal ridge, otobasion superiorand otobasion inferior. Also indicated are the directions superior &inferior, and anterior & posterior;

FIG. 2e is a further side view of a head. The approximate locations ofthe Frankfort horizontal and nasolabial angle are indicated;

FIG. 2f shows a base view of a nose;

FIG. 2g shows a side view of the superficial features of a nose;

FIG. 2h shows subcutaneal structures of the nose, including lateralcartilage, septum cartilage, greater alar cartilage, lesser alarcartilage and fibrofatty tissue;

FIG. 2i shows a medial dissection of a nose, approximately severalmillimeters from a sagittal plane, amongst other things showing theseptum cartilage and medial crus of greater alar cartilage;

FIG. 2j shows a front view of the bones of a skull including thefrontal, temporal, nasal and zygomatic bones. Nasal concha areindicated, as are the maxilla, mandible and mental protuberance;

FIG. 2k shows a lateral view of a skull with the outline of the surfaceof a head, as well as several muscles. The following bones are shown:frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal,temporal and occipital. The mental protuberance is indicated. Thefollowing muscles are shown: digastricus, masseter sternocleidomastoidand trapezius;

4.3 Pap Device

FIG. 3 shows an example PAP device suitable for implementation withexamples of the present technology;

4.4 Patient Interface

FIGS. 4, 5 and 6 show a patient using an example under the nose patientinterface of the present technology;

FIG. 7 is a patient side or proximate view of the cushion of the patientinterface of FIG. 4;

FIGS. 8 and 9 are cross sectional views of the patient interface of FIG.4, particularly showing the nasal region of the patient interface ofFIG. 7;

FIG. 10 illustrates facial contact regions of an under the nose mask forsome examples of the present technology;

FIG. 11 shows an example frame, cushion support clip and cushioncomponents in some forms of a patient interface of the presenttechnology;

FIG. 12 is an illustration of the example frame component of FIG. 11;

FIG. 13 is an illustration of the example cushion support clip componentof FIG. 11;

FIG. 14 is an illustration of another example cushion support clipcomponent;

FIGS. 15, 16 and 17 show cross sectional views of different cushionsupport regions for the cushion support clip component;

FIG. 18 is a further illustration of another example cushion supportclip of the present technology;

FIG. 19 illustrations and example force profile that may be achievedwith some examples of the present technology;

FIGS. 20 and 21 show perspective views of a cushion support clipcomponent coupled with a frame component;

FIGS. 22 and 23 illustrate a side view and a perspective view,respectively, of a cushion coupled to a cushion support clip;

FIG. 24 illustrates an example flat contact surface cushion suitable forimplementation with some embodiments of the present technology; thefigure also includes a callout showing a cross-sectional view of thecushion. Notably, because of the square profile, the surfaces forcontacting the underlying supporting surface and the patient's face areboth flat);

FIG. 25 illustrates an example curved surface cushion suitable forimplementation with some embodiments of the present technology; thefigure also includes a callout showing a cross-sectional view of thecushion. The flat surface of the cushion is for contacting theunderlying supporting surface and not the patient's face;

FIGS. 26 and 27 illustrate the assembly of the cushions of FIGS. 24 and25 respectively with a frame;

FIG. 28 illustrates a scalloped nasal region of a cushion in someexamples of the present technology;

FIG. 29 illustrates a cushion having left and right nasal supportprotrusions;

FIGS. 30 and 31 show plan and side views respectively of the cushion ofFIG. 29 in a under-the-nose mask assembly of the present technology;

FIGS. 32A and 32B illustrate a clip and frame connector for someexamples of the present technology;

FIGS. 33A and 33B illustrate another clip and frame connector for someexamples of the present technology;

FIGS. 34 illustrates a still further clip and frame connector for someexamples of the present technology; and

FIGS. 35A and 35B illustrate yet another clip and frame connector forsome examples of the present technology.

FIGS. 36 and 37 illustrate a foam mask, with headgear, configured forsealing with the mouth and over the nasal bridge.

FIG. 38 is another view of the foam mask of FIG. 36 without theheadgear.

FIG. 39 is an illustration of separated components of a foam cushionassembly such as for the foam mask of FIG. 38.

FIG. 40 shows the foam cushion assembly with the coupled components ofFIG. 39.

FIG. 41 illustrates mask sealing with a foam cushion in a nasal regionwith the mask of FIG. 39.

FIG. 42 shows regions of a clip component of the mask of FIG. 39.

FIGS. 43, 44 and 45 are cross sectional views a portion of a foamcushion in some embodiments of the present technology such as for anasal bridge region, a side of nose region and side of mouth region.

FIG. 46 illustrates several example cross sectional geometries for afoam cushion of any of the foam cushion patient interface embodiments ofthe present technology.

FIG. 47 illustrates foam cushion and clip components, as separatecomponents, as well as in an assembled configuration of the presenttechnology.

FIG. 48 is a cross sectional view of a cushion assembly in some versionsof the present technology having multiple clip components and a foamcushion.

FIG. 49 shows various regions of a flexible clip component for a foamcushion mask.

FIG. 50 shows the clip component of FIG. 49 with an optional foamlocation ridge.

FIGS. 51, 52, 53 and 54 illustrate various cross sectional geometriesfor various regions of the clip component of FIG. 49 such as for a nasalbridge region, a side of nose region, side of mouth region and a bottomof mouth region.

FIGS. 55 and 56 are cross sectional views of several example cushionassemblies coupled with a mask frame.

FIG. 57 illustrates several example retention elements for coupling afoam mask cushion assembly with a mask frame.

FIG. 58A is a side view of a cushion and clip assembly in some versionsof the present technology.

FIG. 58B is a cross sectional view of the cushion assembly of FIG. 58A.

FIG. 59 is a cross section view of a mask and foam cushion assembly insome versions of the present technology.

FIG. 60 is a cross sectional view of a flexible shell for a foam maskassembly.

FIG. 61 is an exploded view of components of a foam mask assembly withthe shell of FIG. 60.

FIG. 62 illustrates the foam mask assembly of FIG. 61 on person.

FIGS. 63A and 63B illustrate assembly of a foam cushion and clip in someexamples of the present technology.

FIGS. 64, 65, 66A and 66B illustrate assembly of a foam cushion and maskframe with various clips.

FIGS. 67 and 68 show a foam cushion and clip assembly with some versionsof the present technology.

FIG. 69 is an illustration of a foam cushion suitable for someembodiments of the present technology;

FIGS. 70, 71, 72 and 74 illustrate cross sectional geometries of anexample clip such as for the foam cushion of FIG. 69.

FIG. 73 is a side view of a further example clip assembly for a foamcushion.

FIG. 76 is a cross sectional view of portions of a foam cushion maskassembly.

FIG. 77 is a perspective view of an example foam cushion mask assemblyof the present technology.

FIG. 78 is a bottom side view of the foam cushion mask assembly of FIG.77.

FIG. 79 is a perspective view of a mask frame component of the foamcushion mask assembly of FIG. 77.

FIG. 80 is a perspective view of a cushion assembly of the foam cushionmask assembly of FIG. 77.

FIG. 81 is a bottom side view illustrating assembly of the mask framecomponent and cushion assembly of FIGS. 79 and 80.

FIG. 82 is a cross sectional view of portions of a foam cushion maskassembly.

FIG. 83 illustrates various performance regions of a foam cushion of thepresent technology.

FIG. 84 is a side view of a foam cushion assembly illustrating a pivotpoint.

FIG. 85 illustrates cushion pressure performance of example foam cushionassemblies of the present technology.

FIG. 86 illustrates cushion roll-in performance of example foam cushionassemblies of the present technology.

DETAILED DESCRIPTION OF THE INVENTION

Before the present technology is described in further detail, it is tobe understood that the technology is not limited to the particularexamples described herein, which may vary. It is also to be understoodthat the terminology used in this disclosure is for the purpose ofdescribing only the particular examples discussed herein, and is notintended to be limiting.

4.5 Treatment Systems

In one form, the present technology comprises apparatus for treating arespiratory disorder. The apparatus may include a flow generator orblower for supplying pressurised respiratory gas, such as air, to thepatient 1000 via an air delivery conduit, such as a tube, leading to apatient interface 3000.

4.6 Therapy

In one form, the present technology may involve a method for treating arespiratory disorder by applying positive pressure to the entrance ofthe airways of a patient 1000.

4.6.1 CPAP for OSA

In one example, the present technology may involve a method of treatingObstructive Sleep Apnea in a patient by applying continuous positiveairway pressure to the patient with a patient interface describedherein. Other positive pressure treatment therapies may also be provided(e.g., bi-level CPAP, etc.)

4.7 Pap Device 4000

An example PAP device 4000 in accordance with one aspect of the presenttechnology may include mechanical and pneumatic components 4100,electrical components 4200 and is programmed to execute one or morecontrol methodologies or algorithms, such as to control providing thecontinuous positive airway pressure or any one or more of the positivepressure treatment therapies. The PAP device may include an externalhousing 4010, which may be formed in two parts, an upper portion 4012 ofthe external housing 4010, and a lower portion 4014 of the externalhousing 4010. In alternative forms, the external housing 4010 mayinclude one or more panel(s) 4015. The PAP device 4000 may include achassis 4016 that supports one or more internal components of the PAPdevice 4000. In one form a pneumatic block 4020 is supported by, orformed as part of the chassis 4016. The PAP device 4000 may include ahandle 4018.

The pneumatic path of the PAP device 4000 may include an inlet airfilter 4112, an inlet muffler 4122, a controllable source 4140 of air atpositive pressure (preferably a blower 4142), and an outlet muffler4124. One or more pressure sensors 4272 and flow sensors 4274 may beincluded in the pneumatic path.

An example pneumatic block 4020 may include a portion of the pneumaticpath that is located within the external housing 4010.

The PAP device 4000 may have an electrical power supply 4210, one ormore input devices 4220, a processor, a pressure device controller, oneor more protection circuits, memory, transducers, data communicationinterface and one or more output devices. Electrical components 4200 maybe mounted on a single Printed Circuit Board Assembly (PCBA) 4202. In analternative form, the PAP device 4000 may include more than one PCBA4202.

The processor of the PAP device 4000 may be programmed to execute aseries of algorithm modules in use, preferably including pre-processingtransducer signals module, a therapy engine module 4320, a pressurecontrol module, and further preferably a fault condition module.

5.4 Patient Interface 3000 5.4.0 Features

A patient interface 3000 in any versions of the present technology maytypically include optional features such as a seal forming structure3100, a plenum chamber 3200, positioning and stabilizing structure 3300,vent 3400, decoupling structure 3510, connection port 3600, foreheadsupport 3700, anti-asphyxia valve 3800 and/or one or more ports 3900.Such features may be considered in reference at least to the examples ofFIGS. 4 and 36.

5.4.0.1 Seal-Forming Structure 3100

In one form of the present technology, a seal-forming structure 3100provides a sealing-forming surface, and may additionally provide acushioning function.

A seal-forming structure 3100 in accordance with the present technologymay be constructed from a soft, flexible, resilient material such assilicone or other materials and structures described throughout thisspecification.

In one form, the seal-forming structure 3100 may include a sealingflange and may further include a support flange. The sealing flange maybe a relatively thin member with a thickness of less than about 1 mm,for example about 0.25 mm to about 0.45 mm, that extends around theperimeter of the plenum chamber 3200. Support flange may be relativelythicker than the sealing flange. The support flange can be disposedbetween the sealing flange and the marginal edge of the plenum chamber3200, and extends at least part of the way around the perimeter. Thesupport flange is or includes a spring-like element and functions tosupport the sealing flange from buckling in use. In use the sealingflange can readily respond to system pressure in the plenum chamber 3200acting on its underside to urge it into tight sealing engagement withthe face.

In one form the seal-forming portion of the non-invasive patientinterface 3000 comprises a pair of nasal puffs, or nasal pillows, eachnasal puff or nasal pillow being constructed and arranged to form a sealwith a respective naris of the nose of a patient.

Nasal pillows in accordance with an aspect of the present technology mayinclude: a frusto-cone, at least a portion of which forms a seal on anunderside of the patient's nose; a stalk, a flexible region on theunderside of the cone and connecting the cone to the stalk. In addition,the structure to which the nasal pillow of the present technology isconnected includes a flexible region adjacent the base of the stalk. Theflexible regions can act in concert to facilitate a universal jointstructure that is accommodating of relative movement—both displacementand angular—of the frusto-cone and the structure to which the nasalpillow is connected. For example, the frusto-cone may be axiallydisplaced towards the structure to which the stalk is connected.

In one form of a non-invasive patient interface 3000, a seal-formingportion forms a seal in use on an upper lip region (that is, the lipsuperior) of the patient's face.

In one form the non-invasive patient interface 3000 comprises aseal-forming portion that forms a seal in use on a chin-region of thepatient's face.

Additional features of the seal-forming structure may be furtherconsidered in reference to the additional details of this specification.

5.4.0.2 Plenum Chamber 3200

Preferably the plenum chamber 3200 has a perimeter that is shaped to becomplementary to a surface contour of the face of an average person inthe region where a seal will form in use. In use, a marginal edge of theplenum chamber 3200 is positioned in close proximity to an adjacentsurface of the face. Actual contact with the face is provided by theseal-forming structure 3100. Preferably the seal-forming structure 3100extends in use about the entire perimeter of the plenum chamber 3200.

5.4.0.3 Positioning and Stabilising Structure 3300

Preferably the seal-forming structure 3100 of the patient interface 3000of the present technology is held in sealing position in use by thepositioning and stabilising structure 3300.

5.4.0.4 Vent 3400

In one form, the patient interface 3000 includes a vent 3400 constructedand arranged to allow for the washout of exhaled carbon dioxide.

One form of vent 3400 in accordance with the present technologycomprises a plurality of holes, for example, about 20 to about 80 holes,or about 40 to about 60 holes, or about 45 to about 55 holes.

Preferably the vent 3400 is located in the plenum chamber 3200.Alternatively, the vent 3400 is located in a decoupling structure 3510,e.g. a swivel.

5.4.0.5 Decoupling Structure(s) 3510

In one form the patient interface 3000 includes at least one decouplingstructure 3510, for example a swivel or a ball and socket.

5.4.0.6 Connection Port 3600

Connection port 3600 allows for connection to the air circuit 4170.

5.4.0.7 Forehead Support 3700

In one form, the patient interface 3000 includes a forehead support3700.

5.4.0.8 Anti-Asphyxia Valve 3800

In one form, the patient interface 3000 includes an anti-asphyxia valve3800.

5.4.0.9 Ports 3900

In one form of the present technology, a patient interface 3000 mayoptionally include one or more ports that allow access to the volumewithin the plenum chamber 3200. In one form this allows a clinician tosupply supplemental oxygen. In one form this allows for the directmeasurement of a property of gases within the plenum chamber 3200, suchas the pressure.

5.4.1 Sub Nasal Sealing

A non-invasive patient interface 3000 in accordance with one example ofthe present technology may be considered with reference to FIGS. 4-7.The patient interface may include any of the following features: aseal-forming structure 3100, such as a cushion 3110, a plenum chamber3200, a positioning and stabilising structure 3300, such as one or moreheadgear vectors, and a connection port 3600 for connection to anair/gas circuit 4170. In some forms, one or more such features may beprovided by one or more physical components. In some forms, one physicalcomponent may provide one or more functional features. In use, theseal-forming structure 3100 may be arranged to be in direct contact withthe patient's skin and surround an entrance to the airways of thepatient so as to facilitate the supply of air at positive pressure tothe airways.

For example, as shown in FIGS. 4-7, the patient interface may beconfigured as a mask to provide a sealed interface with the mouth andnares of a patient so as to direct a breathable gas under pressure toboth the mouth and nares. Such a mask may be configured to be asubstantially under-the-nose mask. As illustrated, the plenum chamber3200 may be formed by a frame 3500 and cushion 3110. The cushion 3110may also serve as the seal forming structure 3100. The frame may beadapted for coupling with a respiratory treatment apparatus so as topermit communication of a pressurized gas to a respiratory system of apatient from the respiratory treatment apparatus. The cushion may thenbe adapted to couple with the frame.

In some cases, as illustrated in FIG. 7, the cushion may form a sealwith a substantially under nose seal portion UNSP and a mouth sealportion MSP. Such a configuration may be considered in reference to theillustration of FIG. 10. The under nose seal portion may be formed by asub-nasal ridge 3131 that forms a semi-peripheral sealing boundary aboutboth nares of the patient. In this regard, such a seal may be achievedwith both nares and the mouth while in some cases avoiding a sealportion or other mask contact structure at a central region of the lipsuperior LS. Such a mask may provide a more open and comfortable feelfor users such as when compared to mouth masks that may be combined withnasal prongs, while still providing an effective seal.

Obtaining a seal with a single cushion that seals both over the mouthand under the nares of the nose can be difficult to achieve with a nasalcradle design that uses standard silicone cushion materials. It has beendiscovered that the anthropometrical variations of facial features arelarge. Some materials, such as standard silicone, may have insufficientflex to achieve both seal and comfort, especially with respect to theintricate facial features surrounding the nose and the mouth.

In some cases, this problem may be overcome by an implementation offoam, such as a semi-open (or semi closed) cell foam. In some examples,the cushion may be a foamed silicone material or a polyurethane foam,etc. In some cases, a very low durometer thermoplastic elastomers (TPE),thermoplastic polyurethane (TPU), thermoplastic polyurethane (TPV),silicone or rubber material might be implemented. The compliant natureof foam allows it to, under relatively small tension force, compressinto intricate facial features and affect a good seal. This, combinedwith the easy adaptability and softness experienced by the patient,provides for a relative fast and easy mask set-up. The porosity of thefoam also exhibits better breathability than silicone and may permitwicking away of moisture from the face. Thus, the use of foam may beassociated with better cooling and reduced discomfort in the areas ofcontact or sealing.

In some cases, the cushion and/or frame may define a single chamber,such as the plenum chamber 3200 that is illustrated in FIG. 7, whichcovers the patient's mouth and the nares of the nose from underneath. Asdiscussed in more detail herein, the cushion may have a substantiallyoval and/or triangular shape. The sealing surface may continuouslyextend substantially in two plains—one plane that allows it to seal withthe mouth and a second plane that facilitates the seal under thepatient's nostrils. The second plane may form an angle with respect tothe first plane. The angle may be approximately close to ninety degreesor approximately perpendicular, but may be slightly larger or slightlysmaller. Such an angle may approximate the nasolabial angle. Such asingle chamber foam cushion may be designed to attach to a framedirectly or by way of a clip as discussed in more detail herein.

The seal around the mouth and the nares of such a mask can be producedthrough the interaction between the patient's face and the combinedreaction of the assembly (e.g., frame, flexible clip, and/or cushion)and subject to tension from headgear. The structures of the componentswhen assembled can work together to provide variable amounts ofcompression around the nose and mouth so that an effective seal isproduced in these areas.

FIGS. 8 and 9 show a cross sectional view of a sub-nasal region of aportion of the seal including an example sub-nasal ridge 3131. Thefigures illustrate a mechanism for achieving the seal in the sub-nasalregion.

When the nose is applied onto the cushion (e.g., foam) in the region ofthe sub-nasal ridge, the headgear may be tightened. The headgear vectorshelp to enforce a seal at the periphery of both of the nares through thecombination of the cushion (e.g., foam) and/or the cushion supportstructure 8800 (e.g., clip 3535) rolling inwards (illustrated by arrowsRR in FIG. 9) and closing around the periphery of the nares. Theflexibility of the combination of cushion and/or cushion supportstructure can enable the cushion to align to the alar angle and to theNasolabial angle of the nose. As the headgear vectors are furthertightened, a greater sealing force can be applied to the periphery ofthe nares. The reaction force in the cushion and the cushion support(e.g., clip and/or frame), caused by the rolling and compression ofthem, result in a reaction vector that radiates (approximatelyperpendicularly) from the frame support back towards the patient.Moreover, the generated gas pressure (e.g., from a flow generatorcoupled to the mask assembly) that accumulates inside the mask plenumchamber can push the cushion (e.g., foam) outwards. This can ensure anopening up of the air passage to the nostrils and may also compress thecushion upwardly (towards the patient's sub-nasal region), thusgenerating sealing pressure around the nares.

In some cases, there may be a potential for occlusion of the nares bysome cushions during set-up or use. When the seal around the nares isassociated with the compression of some foams, it can lead to nasalocclusion occurring at mask set-up before pressure is applied to themask. In order to minimize the potential for occlusion, a balance can beattained between the foam thickness, the foam profile around theperiphery of the nares and cantilever spring characteristics of thesupport structure (e.g., clip if used).

In the case of implementation of foam, a thin foam section, such as inthe nasal region may be suitable. For example, a foam thickness of about8 to 20 mm (e.g., 13 mm) may noticeably improve/prevent set-upocclusion. In some cases, the foam internal profile may be alignedand/or shaped to match the nares opening such as at their periphery. Asoft elastic material (such as silicone, TPE, TPU etc.) may beimplemented as a material such as for the cushion support. Such amaterial can be configured to pass on a light cantilever spring affectonto the nose.

During a pressure treatment, such as a CPAP treatment, occlusion may beavoided at the nares. The internal profile (as illustrated in FIG. 9) ofthe foam cushion can provide relief around the nares. Generally, thefoam may be compressed around the periphery of the nares by the internalCPAP pressure inflating the nostrils. In order to achieve a suitable andcomfortable seal, the foam rigidity should be no greater than thereaction force generated by the internal CPAP pressure inflating thenostrils. This situation can hold the nares open during CPAP and noocclusion will result.

The cantilever spring force of the cushion support (e.g., clip and/orframe) can be soft enough to allow the nose to press into the foamcushion at set-up without occluding the nares. Conversely, the springforce of the cushion support can provide enough reaction force to pressthe foam cushion into all the sealing zones of the mask. This may besignificant for areas such as at the corners of the nose.

Example components for a mask assembly of the present technology arefurther illustrated in FIGS. 11 through 23. In some cases, as shown inFIG. 11, the frame 3500 may be a separable component from the clip 3535and the cushion. As seen in FIG. 12, the frame may include a set offasteners 3537. The fasteners may be employed for connection of headgear (not shown) to position and support the mask assembly for use. Theframe may also optionally, include a vent 3400. In one form, the vent3400 may be constructed and arranged to allow for the washout of exhaledcarbon dioxide. The vent 3400 may be formed by a plurality of holes, forexample, about 20 to about 80 holes, or about 40 to about 60 holes, orabout 45 to about 55 holes. The vent 3400 may be located in the plenumchamber 3200. Alternatively, the vent 3400 may be located in adecoupling structure, e.g. a swivel or other coupler.

The frame may typically include a connection port 3600. The connectionport 3600 allows for connection to an air circuit 4170, such as for aconnection with a respiratory treatment apparatus or flow generator.Such a connection to an air circuit may be by way of a decouplingstructure as previously mentioned. In some cases, the patient interface3000 may include an anti-asphyxia valve (not shown). Optionally, theframe may include one or more additional ports. Such additional portsmay permit access to the volume within the plenum chamber 3200. Forexample, such a port may permit introduction of a supply of supplementaloxygen. Such a port may also serve as a coupler or housing for a sensorfor direct measurement of a property of the gases within the plenumchamber 3200, such as pressure.

The frame may contain a flange 3515 around its rear (patient proximateside) periphery such as the one illustrated in FIG. 12. This flange mayvary in angle and width around the periphery of the plenum chamber inorder to follow the curvature of the sections of the face where a sealis to take place. The flange may extend generally parallel to thoseareas near where the seal is to exist on the patient's face. A varyingangled flange can work together with the headgear vectors to impart adesired amount of cushion compression to the varying parts around themouth and the nares to achieve a comfortable and effective seal.

In some cases, the mask assembly may employ a clip 3535 as illustratedin FIG. 13 or FIG. 14. The clip may be releasably attachable with theframe so as to permit a convenient replacement of the cushion that maybe applied to the clip. In this regard, FIGS. 20 and 21 illustrate theclip (without a cushion) coupled to the frame. However, any one or moreof the features of the clip described herein may optionally beintegrated with the structure of the frame itself and the cushionapplied thereto.

In some cases, the clip's profile can assist in imparting form to thecushion so as to configure the cushion into its multi-dimensional shape(e.g., multi-plane) suitable for conforming to the person's face so asto form a good seal in an under-the-nose configuration. In this regard,as seen in FIGS. 13 and 14, the clip may be formed with a bend or angledregion ABR. The angled region ABR permits an angle between a nasalplateau region NPR and a mouth periphery region PR. An approximatelynasolabial angle ANA may be formed by a plane of the mouth peripheryregion and a plane of the nasal plateau region. When the cushion isapplied to the clip (and/or frame) such as shown in FIGS. 22 and 23, thecharacteristics of these regions may be imparted to the cushion in thecase that the cushion is not already formed with such regions.

Alternatively, a 2D flat clip may be used. In this case the 3D shape isimparted to the flexible clip/cushion combination by attachment onto a3-D shaped frame.

Generally, the clip may be permanently coupled to the frame or includeconnectors 3536, such as those illustrated in FIGS. 13, 22 and 23 tofacilitate its removable coupling with the frame. These elements may beformed around one side (e.g., the lower periphery or distal side) of theclip where it interfaces with the frame. Additional examples of suchconnection elements are explained in more detail herein with referenceto FIGS. 32-35. The clip's opposing side (e.g., upper peripheral surfaceor patient proximate side) provides a connection or landing surface forattachment of the cushion (e.g., the foam ring). In this regard, thefeatures of the clip may serve as a suspension for the cushion.

As the wall thickness of the clip is relatively small (i.e. fewmillimeters) the clip's body may generally be approximated with a curvedsurface. The cross-sectional profile of the clip around the clip'speriphery may differ in different sections of the clip so as to providedifferent regions of flexibility/rigidness to the cushion. Examples maybe considered with reference to the cross sectional views of FIGS. 15,16 and 17. For example, the clip may be formed so as to have an open orconcave wall 3535W with a cross-section along the clip's periphery thatmay vary in geometric shape. These cross-sectional shapes may be, forexample, formed as a U-shape such as that shown in FIG. 15, an L-shapesuch as that shown in FIG. 16, or a C-shape such as that shown in FIG.17. Other examples may include I-shape or Z-shape cross sectionalconfigurations. In some cases it may be formed with some or all of thesewall formations. The opening of each shape (shown in FIGS. 13, 15, 16and 17 with reference character SO) can be directed inwardly towards thecenter or plenum chamber of the mask. These different wall structuresmay have different flexibility characteristics. Such cross-sectionalshape(s) can enable the clip to act as a spring or cantilever-typespring. Such a spring configuration can permit the foam cushion tofurther conform to the face and compress towards it once alignment hasbeen achieved, improving cushion compliance to the face.

Accordingly, the clip (or frame) may be formed with a flexibleperipheral lip that variably supports the foam cushion. Pressure withinthe plenum chamber formed between the mask frame, clip, cushion and theface of the patient, acts on the inside of the clip section (e.g., theshape opening SO of the wall) and cushion and pushes the peripheral lipand the cushion towards the patient's face, thereby reinforcing the sealcreated by the cushion. As pressure increases, so does the forcecreating the seal. As such, the wall of the clip may also be chosen tohave thickness and flexibility to allow the air pressure to create anair spring effect, further contributing to the compliance of the seal.

As previously mentioned, the wall geometry around the periphery of theclip may vary in order to alter the stiffness or flexibility around thenose and mouth sealing regions. Different stiffness/rigidity may beachieved in these different sections of the face to achieve a balancebetween good seal, comfort and stability. For example, around the nose,a softer seal can be achieved as the nose is sensitive to pressure,whereas the sides of the mouth can withstand larger sealing pressureswithout discomfort. Thus, the flexibility of the clip (or frame) mayimpart these different flexibility characteristics.

In some such examples, support for the cushion in the nasal sealing areamay be formed as the flexible cross-section “U” geometry illustrated inFIG. 15. The clip wall (concave wall 3535W) may then have a cushionsupport surface 3538 and a frame coupling surface 3539 for a connectoras discussed herein. In some cases, support for the cushion in thesealing area at the sides of the mouth may be formed by a flexible wallhaving a cross sectional shape resembling an “L” geometry as illustratedin FIG. 16. Moreover, support for the cushion in the sealing areal atthe lower part of the mouth, may be formed by a flexible wall having across sectional shape resembling the “C” geometry as shown below in FIG.17.

Similarly, with respect to at least the example clip shown in FIGS. 14,18 and 19, two active portions of the clip's structure are theperipheral lip 3540 that form an effective cantilever over-hang portionand a middle transverse portion 3541 of the clip's periphery between theframe coupling surface 3539 and the cushion support surface 3538. Bothof these components can act as springs and provide a sealing reactionforce through their deformation. Distribution of the clip-contributedsealing force around the mouth may be governed by the clip's materialand geometry. Moreover, the force may be controlled by the userdepending on the amount of tightening of the headgear of the mask.

In this regard, the combination of a foam cushion and the flexiblesupport structure of the clip can provide reasonable results. However,for achieving optimal seal comfort, the flexible clip may be providedwith an oversized peripheral lip that increases the support of a foamcushion width that may be larger than the support surface of theperipheral lip. Such variations in the width of the peripheral lip canproduce different reaction forces around the periphery of the mouthcushion. Beam and bending principles may show that, in isolation, ashorter peripheral lip will produce a stiffer mechanical system as therewill be less clip deflection for a certain unit force than there will befor a longer peripheral lip.

Such a clip may be considered with reference to the cushion supportstructures of FIGS. 14, 18 and 19. Sizing of the width (shown in FIG. 18as arrow LW) of the peripheral lip also allows for introducingvariations in the seal geometry. For example, different (e.g., narrower)widths in the peripheral lip area proximate to the nose and mouth mayhelp to achieve different reaction sealing forces in these areas. Asillustrated in FIG. 18, the profile for the clip's peripheral lip may bechanged to that shown by the dashed line. The resulting clip isillustrated in FIG. 19. As illustrated, a shorter lip width (shown atarrow SLW) may be provided at the peak of the nasal plateau region forless flexibility. A relatively longer lip width (shown as arrows LL) maybe provided proximate the centrally open lip superior region COLS formore flexibility. As shown in FIG. 19, the reaction force of such a clipcan vary around the periphery as a result of such changing widths of theperipheral lip or cantilever arm. In some such cases, the width of thecushion may be similarly varied. However, the width of the cushion maybe relatively constant despite the change in support structure widtharound its periphery such as shown in FIG. 23. In this sense, the foam'sgeometry profile may not follow the clip's geometry exactly. As aresult, the final force profile of the mask can be affected by thecombination of the clip and the compressing foam.

Adjustments to flexibility around the sealing periphery may also beachieved by varying the thickness of the lip. For example, a lipthickness value along the sides of the mouth toward the nasal peakportion may be approximately double that of the thickness along thebottom of the mouth. Such a ratio can provide less flexibility in thenasal region and relatively more flexibility in the lip inferior region.In one such example, and depending on the clip materials, peripheral lipthickness may be in a range of about 1.5 mm to 2.5 mm, such as about a2.2 mm (+/−0.1 mm) relatively constant thickness from the regionproximate to the sides of the mouth to the nasal peak region. The regionof the peripheral lip proximate to the lip inferior (around the bottomof the mouth) may be in the range of about 0.75 mm to 1.25 mm, such asabout a relatively constant 1.0 mm (+/−0.1 mm) thickness.

Generally, the body depth (illustrated in FIG. 14 as arrow BD) may berelatively constant about the periphery of the clip. In the example ofFIGS. 14, 18 and 19, the body depth of the clip (that portion that doesnot connect to the cushion or the frame) may be in a range, for example,from about 8 mm to 15 mm or for example a depth in a range of about 11mm to 13 mm.

In some cases, additional features may be formed with or applied to thecushion support structure to further affect the performance of the seal,such as flexible nasal protrusions. Such an example is illustrated withrespect to the clip of FIG. 13, which is also shown applied to a framein FIGS. 20 and 21. In the example of FIG. 13, the clip also containsextra cantilever protrusions 3561 that may further serve as cantileversprings. With these elements, the clip can press the foam intohard-to-seal areas such as the corners of the nose, effectivelyproviding a variable level of cushion compliance.

As previously mentioned, the cushion support (clip or frame), orportions thereof, may be molded from different grades of thermoplasticelastomers TPE. Grades of different hardness may be used. Generally, aTPE material may be more beneficial to silicone as it may be more easilymolded onto some cushions (e.g., foam) and its processing time may befaster than silicone. However, other elastic or flexible materials maybe used such as thermoplastic polyurethane (TPU), thermoplasticpolyurethane TPV or rubber, etc. By way of further example, in somecases, the flexible support structure (e.g., clip) may be formed withsilicone, such as a room temperature vulcanizing RTV silicone.

As mentioned previously, because of their flexible nature, the cushionand cushion support structure (e.g., clip) work in unison to respond tothe compression force imparted to the frame by the headgear vectors.However, the cushion, such as when foam is used, may play a greater partin conforming to the face of the user purely because it is the softercomponent and therefore may compress more. Eventually, when the headgeartension has been applied and the frame is pulled towards the patient'sface, the foam and flexible support structure will reach an equilibriumshape, in which a seal is created.

Example cushions for the mask assemblies of the present technology areillustrated in FIGS. 24 and 25. The cushions may be foam and form atriangular or oval shaped ring and may have a common nasal and mouthaperture. The corners may be rounded. In the example of FIG. 24, thecushion has a generally flat patient contact surface PCS. In some suchcases, the edges may be rounded. For example, as illustrated in FIG. 25,the cushion profile along is periphery may have a generally curvedpatient contact surface PCS. Other cushion profiles may also beimplemented. The frame or clip contact side of the cushion may begenerally flat or otherwise conform to the contact surface of thecushion support structure.

With these example generally uni-planar cushions, when connected to theclip or frame as illustrated in FIGS. 26 and 27, the cushion may deformto a multi-planar shape as previously discussed that is better forsealing. The triangular shape, when so deformed, enables the cushion toproduce its seal around the outer periphery of a portion of the nares,into the corners of the nose and around the side and the bottom of themouth while maintaining a substantially under-the-nose configuration andproviding for a centrally open lip superior region. Thus, the mask mayhave a substantially non-contact area in the central lip superior regionbetween the upper vermillion and the columella in the sub-nasal region.Moreover, this non-contact region may be within the plenum chamberduring use.

While the cushions of FIGS. 26 and 27 are generally uni-planar and aredeformed by the frame or clip to have their multi-planar useconfiguration (e.g., with an nasolabial angle between the nasal plateauregion and the mouth periphery region), in some cases the cushion orfoam may be pre-formed or pre-cut in the multi-planar shape consistentwith the shape of the clip or frame.

Generally, there should be an air tight seal between cushion and itssupport structure (e.g., the clip). Various methods may be employed toimplement such a joining of the cushion. For example, the cushion may beadhered to the support structure such as with glue, spray adhesives orhotmelts, etc. In some cases, it may be adhered by ultrasonic welding.In some cases, the cushion may be sewn and adhered. The join may also beimplemented with an intermediary material such as a tape (e.g., a doublesided adhesive tape). In some cases, the support structure (e.g., clip)may be over molded to the cushion.

Similarly, such methods may be employed for joining the cushion to theframe, such as without an interfacing clip. In this regard, the framemay provide the shape forming structure and surface to hold the cushion(e.g., foam) in the desired profile for patient sealing. In such anembodiment, the cushion foam may provide some or all of the necessaryspring and softness to effect the seal and provide comfort to thepatient. Otherwise, some of the previously described flexible features(e.g., cantilever components of the clip) may be formed with the frameto assist with the seal and comfort effectiveness. In some suchclip-free cases, some of the flexible properties of the clip may beimparted to the foam by using a secondary layer of cushion rather thanthe clip. Such a secondary cushion layer may be applied to the patientcontact foam layer and may have different flexibility/rigidityproperties when compared to the first foam layer. In such a case, thesecond layer of the dual cushion may be applied directly to the framewithout the clip.

In some cases the foam cushion may be a replaceable item (in someembodiments the replaceable item may include the cushion/clipcombination). The cushion may be directly attached to the frame throughan adhesive membrane located on the foam (or on a surface of therespective clip (either flexible or rigid). In such a case, the cushionmay be simply removed, and a different cushion, with a new adhesivestrip, may then be attached to the reusable frame (or reusable clip). Insome cases, the foam cushion and frame may be co-molded. In some suchcases, the cushion and frame unit may then be discarded together.

In some examples, the cushion 3110 may include additional features. Forexample, as shown in FIG. 28, the cushion may include an indent, such asa scalloped notch 3763, such as in the nasal plateau region of thecushion as an alternative to being a generally flat sealing surface. Theindent may be formed by a semi-peripheral cut of an edge of the cushionin the nasal portion of the seal. In some examples, the cut may form arising edge from a centrally lower position to a radially higherposition. Such a semi-peripheral area may provide a cupping supportaround the nose. The cupping geometry may provide a greater surface area(bearing surface). In this regard, the scalloped edge shape feature mayreplicate the topography under the user's nose. As such, the scallopednotch may also improve sealing in the sub-nasal ridge area and mayprovide improved nasal comfort. It may also serve to minimize noseinflation. The feature may also provide a perceptively distinct landingarea for patients to place their nose, resulting in a more intuitiveset-up. In some cases, the notched area or the nasal plateau region maybe marked to provide an indication of nasal location for userinstallation. For example, the area may have a distinct color withrespect to the remaining areas of the cushion.

The shape of such a notch may be defined from any of the followinganthropometric features: width between the labial insertions of the alarbase; length of the ala; nasal ala-slope angle; inclination of thecolumella; nasal tip protrusion; width of nose. In some cases, the depthof the indent detail may be based on any of: the inclination of thecolumella; patient perception with respect to providing sufficientindication as to where the under nose section of the mask should beworn; sufficient surface to seal around the edge curvature of the nose;sufficient support around the periphery of the nose to prevent the nosefrom blowing out such as due to pressure from a pressure treatment.

Other versions of the geometry of the indent may include a simplechamfered edge following the periphery of the nose. When the foam hassufficient compliance for the chamfer to fit the nose an improved sealcan result. Similarly, other variations in the overall triangular shapeof the scalloped nasal feature may be achieved since foam has sufficientcompliance to conform to facial features in a range of sizes.

As previously mentioned, the indent, such as the scalloped nasal detail,can effectively cup the lower periphery of the nose and may provideadditional surface area for sealing and comfort. Thus, it may work inconjunction with other components of the mask assembly (clip and frame)during use to effectively serve as a seal. In terms of sealing anddepending on the specific anthropology of the nose, the sealinginterface may shift or extend or both, from under the nose to underand/or partially up the sides of the nose. In terms of comfort, theforce applied to the nose from the headgear and the treatment pressurefrom the seal interface, may thereby be distributed over a largersurface area, resulting in better comfort.

The geometry of the indent in the foam cushion can change to accommodatea range of nasal sizes. A nose that is pressed into the scallopeddetail, for example, during set-up of the mask will displace foam untilthe foam conforms to the nose. The flexible spring nature of the cushionsupport structure (e.g., clip and/or frame) can provide a resistiveforce at this stage to prevent the nose from fully pushing through thefoam. Under treatment pressure, the foam can be pressed back against thenose which helps to provide an effective seal.

In some cases, the indent may be manufactured as part of a completecompression cutting process for the cushion. Alternatively, the featuremay be manufactured by a secondary process such as thermoforming,ultrasonic welding or cutting. In some cases, the whole cushionincluding the scalloped nasal detail may be manufactured from a singlecompression cutting or thermoforming process.

In some further examples, the cushion may also include one or moreprotrusions. Such protrusion(s) may be included on the surface of thecushion. For example, one or more protrusions can be so disposed sothat, when the mask is fit on the patient's face, the protrusions extendfurther out of the cushion into a portion of the patient's face. Assuch, the protrusions may provide additional structural support and abetter seal. For example, a set (e.g., pair) of protrusions 3764, suchas one or more approximately oval projections or of another shape, areillustrated in the cushion and mask of FIGS. 29, 30 and 31. Theseprotrusions are disposed so as to extend on the left and right sides ofthe nose (e.g., left and right nasal ala protrusions). For example, eachprotrusion may be configured to ply adjacent to a nasal ala of thepatient. As such, they may assist with buttressing the cushion's seal atthe difficult sealing areas on both sides of the nose. The nasalprotrusions, while useful, are optional. An effective seal in thesedifficult regions may also be achieved by other means, includingincreasing the thickness and varying the shape of the foam cushion inthese areas. For example, a narrowing may be introduced at the sides ofthe nasal area of the cushion to facilitate a better seal.

As previously mentioned, the connection between the clip and frame maybe implemented with various structures. Some examples are illustrated inFIGS. 32 through 35. Generally, in the case of an implementation of aclip, there should be an air tight seal between the clip and the frame.The cushion/clip assembly can be detachable from the frame so as topermit regular replacement of the cushion in the case that the cushionmay have a shorter useful life when compared to the frame.

Some example connection structures for anchoring the clip to the framemay include: tongue and groove geometry; a stretchable periphery skirtto extend around an edge of the frame; a peripheral edge that connectsby interference fit, such as one similar to air-tight food containers; atongue and slot interface with secondary lip seal or gasket present. Insome cases, the connection structures of the clip may correspond toexisting mask frames to permit retrofitting of the cushion designsdescribed herein with existing mask frames.

In the connector example of FIG. 32A and 32B, the clip and frame may becoupled together by a bulbous ridge 3572 and channel 3574. For example,the frame may be formed with the channel and the clip may include theridge. A cross sectional view of the ridge and channel may appear as aball and socket. The soft flexible (e.g., TPE, silicone or otherflexible material) bulbous ridge may be pressed into the rigid channelframe (e.g., plastic) to provide a seal and mechanical retention.Optionally snap fingers 3576 may also aid assembly and componentde-molding.

In the connector example of FIG. 33A and 33B, the clip and frame may becoupled together by a skirt 3578 and flange 3515 such as the flangeextending continuously around the plenum chamber of the frame 3500. Insuch a case, the skirt 3578 of the clip may be a semi-rigid element(e.g., TPE, polypropylene or other similar semi-rigid material)continuously extending around the ring of the clip. Plying the skirt soas to cup it over the flange may then serve as a seal and providemechanical retention.

In the connector example of FIG. 34, the clip and frame may be coupledtogether by a snap shoulder 3580 and engagement cavity 3582 continuouslyor semi-continuously extending around the periphery of the clip andframe. Such a snap may be formed on a rim of the clip 3535. The rim andsnap may be displaced by a more rigid frame upon engagement, such aswhen the snap shoulder, which may be a semi-rigid material (e.g.,plypropylene) is plied into the engagement cavity 3582. The surfaceengagement of the rim and frame may provide a seal and the snap shoulderand engagement cavity coupling can provide a mechanical retention.

In the connector example of FIG. 35A and 35B, the clip and frame may becoupled together by a taper lock (shown in exploded view 3583). In suchan example, a peripheral rim 3702 of the frame, which may be rigid, maybe retained in a peripheral channel 3585 of the clip. A taper element3586 of the frame may couple with a taper receiving channel 3587 of theclip, which may be flexible (e.g., silicone, TPE, etc). The taperelement and the taper receiving channel may be formed so as tocontinuously or semi-continuously extend around the periphery of theclip and frame. The taper element and taper receiving channel may thenaid mechanical retention of the frame and clip components.

5.4.2 Supra Nasal Sealing

Traditional Full Face mask (also referred to as a patient interface)obtains a seal with the user's face by way of a silicone cushion thatseals both around the mouth and over the bridge of the nose. The mainissue with this is that, due to the nature of the silicon material,often comfort issues are experienced by the user (i.e. facial markingsor other skin irritations).

This problem may be overcome by the implementation of foam such as thefoam previously discussed. In some embodiments, the foam cushion can bein direct contact with the patient's skin. The compliant nature of foamallows it to, under relatively small tension force, compress intointricate facial features and affect a good seal. This, combined withthe easy adaptability and softness experienced by the patient, providesfor a relative fast and easy mask set-up. The foam also exhibits betterbreathability than silicone. Thus, the use of foam is associated withbetter permeability (associated by many users with a “different feelingon the face verses silicone”) and reduced discomfort in the areas ofcontact in the sealing areas.

The comfort associated with the permeability of the foam has to bebalanced with the increased leak associated with high permeability. Asin the case of the under nose mask configuration, the foam cushion maygenerally be formed by open cell foam, in which the majority of cellsare open; by closed cell foam, in which the majority of cells are openor by semi-open (or semi-closed) cell foam, which is formed by a mixtureof open and closed cells. In one example, the discussed technology mayuse a semi-open cell foam in which the number of open cells issignificantly higher than that of the closed cells. This ensures limitedpermeability and a smaller leak through the cushion. The specific rangeof permeability values having such limited permeability and foundsuitable for the disclosed technology is discussed later in the text.Other ratios between the number of open and closed cells can also beused. In the case of higher permeability, various actions may have to betaken to mitigate the increased permeability. As discussed elsewhere inthe text, one such action is extending the flexible clip or othernon-permeable membrane to cover the inner surfaces of the foam cushionand reduce the overall permeability. It is envisaged that open cellfoams or closed cell foams may also be used according to the discussedtechnology.

In order to achieve comfortable fit, a good seal and stability, currentFull Face foam masks are larger in footprint when compared to masks withtraditional silicone seals.

In effort to achieve certain flow characteristics, some foam cushionspreviously used are either not permeable or may include a secondarylayer over the foam to stop air from passing through the foam. Bothoptions remove the breathability benefit of a foam seal. Onlytraditional foam full face masks having sealed or non-permeable foamcushions were compatible with current respiratory therapy forobstructive sleep apnea (OSA).

Some prior foam masks also involve separate individual components thattogether form the cushion. In one example, a foam layer may be attachedto a silicon cushion to improve the sealing quality and the comfortassociated with the mask. In some circumstances, such arrangements, maybe large in size and less comfortable, and may make it more difficultfor the user to disassemble, assemble and clean the mask.

In some versions of the present technology, such as when a mask isconfigured for sealing with the mouth and over the nasal bridge as shownin the example of FIGS. 36 and 37, a foam cushion may be implemented.

For example, a foam cushion assembly can be configured to seal aroundthe mouth and over the nasal bridge, and can achieve a comfortable andeffective seal. Such an assembly may include a foam cushion portion anda cushion support structure (e.g., a support clip portion). Here theexpression “over the nasal bridge” should be construed as “across” thenasal bridge and not as “above” the nasal bridge. The support clipportion may be a flexible (or soft) clip portion configured tocomplement the compliance of the cushion so as to allow a reduction inthe size of the cushion. The foam cushion can be externally attached tothe cushion support clip. Such an external attachment can permit thefoam surface of the cushion to be configured for direct contact with apatient's skin.

In one example, the cushion 3810, which may be made with foam, defines asingle area that peripherally covers the patient's mouth and nose(approximately midway up the nasal bridge, but this can vary dependingon the face anatomy of the specific patient). The foam cushion may, forexample, be made from any suitable material such as one or more of thefollowing example materials: Polyethylene, Polyurethane, Ethylene vinylacetate (EVA). In some cases, the foam cushion may be a semi-open closedcell foam, such as one made of polyurethane. The cushion of semi-opencell foam may have a limited permeability such as in the rangesdescribed in more detail in this specification.

The cushion 3810 may have a substantially triangular or pear-like shapewith a sealing face that follows the contours of a user's face. Thesingle chamber foam cushion is designed to be attached to a firstsupport (e.g., flexible) clip 3812 that is itself attached to a second,more rigid, clip 3814 (as shown in FIG. 38) or directly to the maskframe 3816. In one embodiment, the first support clip 3812 can be aflexible clip that is more rigid than the foam cushion, but softer ormore flexible than the second clip 3814. It is the combination of thefoam and a flexible clip that defines the physical properties of theoverall sealing interface. The flexible clip allows the interface toaccommodate major variations, and to successfully conform to thecontours of the patient's face. The compliant nature of the foam cushionprovides micro-adjustment and forms a comfort interface layer thatinteracts with the patient's skin.

In some versions of the cushion assembly or cushion mask may include aprotrusion, or an alignment protrusion, that may be configured, when inuse, to be depressed by a headgear strap so as to apply pressure on arespective region of the foam cushion. For example, a protrusion 3813may optionally be included on the outer surface of the first supportclip 3812 (e.g., flexible support clip) on both sides of the mouth(e.g., both symmetrically located about the mouth), in such a mannerthat a respective headgear strap may pass over each protrusion, as shownin FIG. 37. Such an arrangement may allow for better sealing at thesides of the mouth when dealing with facial width variations. Whentightened, the headgear may depress the protrusion toward the patient'sface. Such a pressure will be transferred to the foam cushion,depressing the cushion towards the patient's face and enhancing thesealing in this region of the mouth. The additional pressure can bemodified by changing either the height of the protrusion, the tension ofthe headgear or both. A height of between 2 mm and 6 mm, 3 mm to 5 mm,and preferably of about 4 mm, is considered sufficient for suchmodification. Instead of being located on the surface of the flexibleclip, the protrusion may be located on the outer surface of the foamcushion or the rigid clip. Protrusions of different height/thickness andlocated on different components (i.e. one located on the rigid clip andthe other on the flexible clip) can also be used, e.g. to create agradient of inwardly directed pressure along the side of the mask. Inanother embodiment, the projection may extend across both the foamcushion and the flexible clip. In yet a further embodiment, a flange maybe formed to extend from the frame to apply inwardly directed force andenhance the seal in a similar manner.

In some examples, the flexible clip or even both the flexible and therigid clips may be omitted by directly applying a foam-only cushionassembly to the frame. Such a design, however, may require the cushionto be of a substantial thickness and height. The implementation of aclip, even of a rigid one, and especially of a flexible clip or acombination of soft and rigid clips as described here, allows reductionin the dimensions of the foam cushion, without compromising oncompliance, sealing and comfort. One role of the rigid clip is tofacilitate removable attachment of the foam/clip assembly to/from theframe for cleaning or replacement. Components of a foam cushion assembly3901 are shown in FIG. 39. An assembled view of the foam cushionassembly 3901 is shown in FIG. 40.

As illustrated in FIGS. 39 and 40, a frame coupling side FCS of a rigidsecond clip 3814 may include structures for removeably coupling thesecond clip to a mask frame 3816. For example, a coupling ridge 4022 maybe provided to engage with a corresponding structure of the mask frame.The coupling ridge 4022 may help to form a seal, such as with aninterference fit, to prevent escape of treatment pressure at contactsurface of the mask frame and the second clip at the frame coupling sideFCS. One or more optional engageable snap elements 4024, may permit asnap-fit or snap-lock of the second clip to the mask frame. Such a snapelement may be flexibly resilient so as to bend against a correspondingreceptacle of the mask frame until a ridge stop 4025 may engage with anedge of the receptacle or aperture of the mask frame. A taper 4027 atthe top edge of the snap element may induce the bending of the snapelement during coupling of the second clip to the mask frame until theridge stop 4025 passes into the receptacle or aperture of the mask frameand thereby locks within the receptacle or aperture of the mask frame.In some cases, the snap element may be formed on the mask frame and acorresponding receptacle may be formed on the second clip. A manualbending of the snap element(s) may then permit the removal of the secondclip from the mask frame.

In one example implementation of the foam, flexible clip and rigid clipare formed together or permanently attached to each other, as shown inFIG. 40, forming an integral cushion assembly. The foam and flexibleclip form the compliant portion of the assembly, while the rigid clipprovides the mechanism to attach the cushion assembly to the mask frame.This allows the cushion assembly to be removed for cleaning and/orreplacement. A rigid clip can enable a rigid connection between thecushion assembly and the mask frame which makes the mask more convenientfor handling and more durable. Thus, the components of the cushionassembly (e.g., the foam cushion, the flexible clip and the more rigidclip) can be permanently attached in one integral assembly. However,alternatively they may be separable elements, as shown in FIG. 39. Thesethree elements may be arranged to be separately formed, assembledtogether, but dissembled and assembled again, if necessary.Alternatively, the foam cushion and the flexible clip can be permanentlyattached to each other, but detachably connected to the rigid clip. Inanother example, the flexible clip and the more rigid clip can bepermanently attached to each other but detachably connected to the foamcushion.

The mechanisms of such removable attachment may be those known in theart and may include adhesive layers (for attaching the foam to theflexible clip), interference fits and snap-locking engagements. Theperiphery of the more flexible components, such as the flexible clip,can also be stretched over the periphery of the more rigid component,such as the frame or the rigid clip.

Any combination of the three components is possible and alternativedesign variants could include a cushion assembly comprising only a foamcushion; a foam cushion and a flexible clip or a foam cushion and a hardclip.

In some cases, a foam cushion may itself be formed as a slip-over foamcover component for other mask components, assemblies or mask cushions.For example, a foam cushion overlay may be formed as or with astretchable engagement skirt. The skirt or foam skirt may then bestretched over an underlying structure defined by any mask component,such as a frame, a clip or even a silicon cushion. Once the foam cushionhas been slipped on to fit over an edge of an underlying component, itcan serve as a comfortable sealing layer contacting the patient's face.As such, the slip-over foam cushion may even serve as an easilyreplaceable cover component to improve comfort of existing silicone orfoam cushion masks.

5.4.2.1 Sealing Mechanism

With the mask example of FIGS. 36 and 37, the foam cushion is arrangedto be in direct contact with the patient's skin. The seal around themouth, the sides of the nose and the nasal bridge is produced throughthe interaction between the patient's face and the combined reactionforce of the frame (which may be applied to the cushion assembly by wayof the hard clip); the flexible clip and the foam cushion, to theheadgear tension. Each of these three components is discussed in moredetail below. These components when assembled together can work inunison to provide variable amounts of foam compression around the noseand mouth so that an effective seal is produced in these areas. In thisregard, the illustration of FIG. 41 shows the mechanism that is createdto, through the combination of these three components, achieve seal.

As illustrated in FIG. 41, by applying the foam cushion onto the user'sface and tightening the headgear vectors (seen in FIG. 37) a seal isgenerated along the foam's contact surface with the patient's face, suchas over the nasal bridge and around the sides of the nose and mouth. Theseal is caused by a combination of foam compression and/or deflectionand compression of the flexible clip.

The flexibility in the combination of foam and flexible clip can enablethe foam mask to conform well to the patient's facial profile.

As the headgear vectors are further tightened, a greater sealing forceSF will be applied.

The reaction forces in the cushion and the flexible clip, caused by thedeflection and compression of the cushion and clip by the headgear,result in a reaction vector that is directed from the frame support andtowards the patient.

The structure of the foam cushion and the flexible clip is such that thetreatment pressure (e.g., CPAP) accumulated inside the mask plenumchamber also acts upon the inner surface of the flexible clip and thefoam, pushing them outwardly and compressing the foam against the user'sface. Thus, the arrangement utilizes further the pressure in the plenumchamber and helps maintaining sealing pressure. As mentioned above,because of their flexible nature, the foam and clip work in unison torespond to the compression force imparted to the frame by the headgearvectors. Eventually, when the requisite headgear tension has beenapplied and the frame is pulled towards the patient's face, the foam andclip will reach an equilibrium shape, in which a seal is created andretained. In some examples, through its greater stiffness, the clip mayprovide a reaction force that is substantially larger than that providedby the foam cushion. The reactions forces of both the clip and the foamcushion may vary along their periphery.

Similarly, the compressed foam may provide relatively small elasticreaction force in some sections of the cushion periphery, and a largerforce in other sections.

Similar to the mask examples previously described in this specification(e.g., sub-nasal mask), the flexible clip may be peripherally andinwardly concave so as to have a concave profile or inwardly concaveshape. This can allow for the pressure to act upon the inner surface ofthe clip so as to enhance the sealing of the mask.

Different portions of the flexible clip can serve different functions.For example, the spring constant provided from the mid area of the shape(e.g., ‘C’) may act as a support beam that creates the main reactionforce in response to the tension force applied by the headgear. Aperipheral lip for supporting the foam can serve as a cantilever thatpresses the foam towards the patient's face to strengthen the sealingengagement. Additionally, the overall open (concave, C-shaped orL-shaped) structure of the clip allows the air pressure in the mask tobe applied to the inside surface of the peripheral lip. This surface islocated opposite to the foam supporting (also sealing) surface. Thus,the mask pressure pushes the peripheral lip, and therefore compressesthe foam cushion towards the patient's face, thus further strengtheningthe sealing engagement and potentially assisting with reducing any airpermeability of the foam. In the absence of the clip the pressure willstill be applied to the foam cushion. However, because of the semi-opencell type of the used foam, the applied pressure may leak through thefoam. Thus, the concave shape of the clip means that at least a portionof the lower surface of the foam cushion 3810 is covered by anon-permeable material of the flexible clip, as best seen in FIG. 41.This can be used to control the leak through the cushion and increasethe pressure within the mask plenum chamber. This concept can be takenfurther and the clip can be extended to cover at least a portion of theouter side wall of the cushion 3810, as long as it does not get incontact with the patient's skin. On the other hand, for various reasons,one may wish to leave some of the surface of the foam exposed. As willbe discussed later in the text, one positive outcome of such a designmay be the fact that a portion of the foam is unsupported by theflexible clip and, as a result, the foam may tend to “roll-in” when theheadgear is tightened. Such a roll-in effect may be beneficial for thesealing in some areas of the nose, for example.

5.4.2.2 Foam Cushion

In the example of the cushion shown in FIG. 42, the foam has a varyingcross section from the bridge of the nose to the bottom of the mouth,and is symmetric through the center plane. During use, he the geometryof the foam is affected by the anthropometric data used in the overalldesign of the flexible clip as well as the specification of the foammaterial (e.g., hardness, compression set, permeability, compressionstress strain, density etc.).

The cushion may be configured with a varying cross section that can bedivided into three regions, nasal bridge MNBR, sides of nose region MSNRand sides of mouth region MMR, with a smooth transition between each ofthe regions. Each section may be configured with a profile that isoptimized for the specific area of the face with which it seals.

The cross section of the foam is designed to take into account of thefollowing, and the geometry is design to address each of the areas:

(a) Comfort

It was found with an increase in the amount of foam (both height andwidth) there is an increase in overall comfort. Depending on thespecific cross section of the first clip, the first clip becomesnoticeable so as to be felt through the foam for heights of about lessthan (<) 8.0 mm. (In the example of FIG. 42, the range for the height ofthe foam is about 8 mm-16 mm. Similarly, the comfort of the cushion wassignificantly impacted for widths less than (<) about 12 mm. For thefoam of an example, the width can be in the range of about 12 mm to 30mm, and may be desirable at about 15-20 mm.

(b) Seal

It was found the seal is improved with an increase in width for thesurface of the foam that is directly in contact with the patient.

(c) Stability

It was found the stability of the seal is negatively impacted by anincrease in the height of the foam, whilst being positively impacted byan increase in the width of the foam.

(d) Encroachment

The main risk of encroachment is the potential for the cushion assemblyto intrude/obstruct the user's eyes. In some cases, the width of thefoam may be reduced in these areas of the eye.

By minimizing either one or both the height and the width of the foamcushion in the noted ranges, one can minimize the overall size of themask.

5.4.2.2.1 Foam Cross Sections

(a)Nasal Bridge Region MNBR—FIG. 43

In some examples a nasal bridge region of the cushion, such as thatillustrated in FIG. 43 may be configured (in its cross section) with atrapezium shape. This may provide good stability characteristics. Thetop corners may be rounded for comfort and for a better aestheticappeal. For example, a width of about 12 mm (or in a range of 0-25 mm)may be suitable for the surface portion that contacts the user's nasalbridge. This may be kept substantially higher than other regions inorder to increase the sealing surface in this region.

(b) Side of nose region MSNR—FIG. 44

In some versions, a side of the nose region of the cushion, such as thatillustrated in FIG. 44, may be configured (in its cross section) with atrapezium shape. This may provide stability characteristics. The topcorners may be rounded for comfort. The width of the surface contactportion at the user's face may be about 6.35 mm (in a range of about(0-14 mm)) in order to avoid the cushion intruding into the patient'seyes.

(c) Mouth Region MMR—FIG. 45

In some versions, a mouth region of the cushion, such as thatillustrated in FIG. 45, may be configured (in its cross section) with atrapezium shape. This may provide good stability characteristics. Thetop corners may be rounded for comfort. The width of about 9 mm (withina range of about 0-17 mm) may be suitable for the surface contactportion and may be a compromise between comfort/seal and overall masksize.

Although these distinct regions have been illustrated with trapeziumcross sectional geometry, other cross sectional geometries shown in FIG.46. Such may include; a rounded top geometry 4621-A, a straight edgerounded top geometry 4621-B, a rectangular geometry 4621-C and arectangular with rounded edges geometry 4621-D. The rounded top geometry4621-A has a cross section with a fully rounded top surface. Thisincreases clearance between the user and the foam and improves overallstability. The rectangular geometry 4621-C has a rectangular crosssection, which may perform similarly to the trapezium geometry, whichfor performance purposes is similar to a rectangular cross section withrounded corners. The rounded corner increases the overall comfort of thecushion since, by removing the sharp corners, not as much foam iscompressed in these areas during use of the mask.

In some examples of the cushion, a combination of geometries can beimplemented in a single foam cushion within and/or between differentregions. For example, the foam may be configured with a transition ofgeometries between regions. In one example, the cushion may transitionfrom a cross sectional geometry having a flat top (e.g., rectangular topfor comfort and a better seal)to a round top to increase clearancearound specific facial areas.

The example cross sectional geometries shown in FIGS. 45 and 46 eachhave a foam height of about 12 mm. However, in some examples, the heightof the foam may also transition between and/or within regions withsuitable heights greater or lesser than 12 mm. Suitable heights may bechosen to change the performance as needed in the individual sections ofthe cushion.

5.4.2.2.2 Foam Manufacture

An example embodiment of the foam may be produced by compressioncutting, but it may be produced by, or with a combination of, any of thefollowing methods including, die cutting, thermoforming, moulding,grinding, compression cutting, etc. For example, the foam may becompression cut to a flat profile as illustrated in FIG. 47. In thisflat profile, the foam's shape is somewhat two dimensional, as its shapeis mainly defined in two dimensions, but is planar in the thirddimension. Once the foam is attached to one or both of the clips (e.g.,soft/flexible) clip, it not only changes its two-dimensional shape, butalso bends in the third plane (dimension) and becomes truly3-dimensional. Thus, the clip(s) may impart contour (such as forvariations to improve facial contact) into the foam when assembled. Inthe example of FIG. 47, the foam is held in a contoured shape by thefirst clip. A better view of the 3-dimensional (3D) aspect of thecushion, in an attached configuration, is shown in FIG. 84. Also,instead of having the 3D shape imparted on the cushion by one of theclips, the cushion itself may be formed in a 3D shape, or such may beimparted to any one or both of the clips and/or the cushion by theframe.

5.4.2.2.3 Assembly Method

The foam can be assembled onto a clip or other mask structure such asthe soft/flexible clip by adhesive (e.g., glue and/or tape); by flamelamination; by moulding (e.g., moulding of foam onto the clip, or viceversa); by welding; mechanical connection between foam and clip; bysewing; etc. The foam may be formed or cut with a generally flat orplanar contour. Although it will have a facial contour when used as amask on a patient (see, e.g., facial contours of cushions of FIGS. 58Aand FIG. 22.) In some cases, the foam cushion of any of the masksdescribed in this specification may simply be bent or deformed to have afacial contour that corresponds to the contour of the clip on which itis installed. Thus, the foam may be dependent on the clip to have afacial contour. However, in some cases, the foam may be formed with thefacial contour such as by moulding or cutting the foam. In such cases,the facial contour of the foam may be independent of any clip or otherstructure.

5.4.2.3 First Flexible Clip (e.g., also Occasionally Referred to as a“Soft” Clip))

As shown in the cross-sectional view of the cushion assembly illustratedin FIG. 48, the first soft/flexible clip includes a cushion couplingportion 4840, a support portion 4842 and a base portion 4844. Thecushion coupling portion 4840 provides a contact surface to which thecushion is attached. The supporting portion 4842 is flexible, but with aspecific degree of rigidity so as to provide appreciable reactionsupport to the cushion when the headgear is tensioned and the mask is inuse. The base portion 4844 attaches to the rigid second clip or, in someembodiments, to the frame. One or more additional support portions 4842,for example having different rigidity/flexibility characteristics, canbe included between the coupling portion 4840 and the base portion 4844.

Again, because of the relative small thickness of its walls (a fewmillimeters) the general shape of the body of the clip is a curvedconcave surface with the opening being directed inwardly towards thecenter of the plenum chamber of the mask. The cross-sectional profile ofthe flexible clip varies in shape, but can generally be described as Lor C, or even Z-shaped, a simple gusset, or variations in wall sectionetc. The open or concave nature of the clip allows the pressure insidethe mask plenum chamber to be applied to the cushion (illustrated by thearrows P4 of FIG. 48) in a way that enhances the cushion-to-patientseal. The support portion 4842 may be generally perpendicular to thesealing plane SP-5 (for example—see the C-shaped cross section and itsrespective support portion 4842 in FIG. 56). The material properties ofthe clip, the shape and the dimensions (in particular the thickness andthe height) of the support portion of the clip can be chosen so that theflexible clip offers appreciable support to the cushion, but at the sametime is also able to, when the mask is in use, change its configurationand act as a cantilever spring. The reaction force associated with therigidity of the clip compresses the attached foam cushion towards thepatient's face, improving the seal to the face, whilst the complianceintroduced (i.e., by the cantilever spring nature of the clip) assiststhe foam cushion to conform to the face. The rigidity of the clip,especially in a lateral direction (up and down or sidewise with respectto the face) also provides lateral stability of the mask. Such stabilityis especially beneficial for wearing the mask at night, when movementsof the patient's head tend to disturb the mask and compromise thesealing engagement.

A minimum height of about 5 mm is desired in the flexible clip to allowfor sufficient movement during usage, so the user does not “bottom out”on the flexible clip. In this context, “bottoming out” can occur whenthe flexible clip has reached its deflection limits or when compressedcompletely flat to a stop and there is a sharp rise in the tension forceacting on the user's face and experienced by the user. The height can bechosen to be a height within a range of about 5 mm to 30 mm, dependingon the area of the face covered by the clip.

The entire flexible supporting clip or the middle support portion 4842may represent a curved surface having, for example, a “Z”, “C” or “L”cross sectional geometry. The cushion coupling portion 4840 may be inthe form of a peripheral lip that connects to the foam to form aneffective cantilever over-hang portion. Depending on the structure andthe material characteristics of the various section of the clipcross-sectional profile (shown in FIG. 48), the cantilever spring effectmay be predominantly confined to a specific portion of the flexibleclip, such as the overhanging lip formed by the cushion coupling portion4840 with respect to the top edge of support portion 4842, or thecombination of portions 4840 and 4842, with respect to the boundarybetween the flexible support portion 4842 and the frame attached portion4844.

When the headgear is tensioned, the support portion 4842 of the clipdeforms and creates a reaction force that tries to return the clip toits original shape. This force depresses the foam towards the patient'sface, enhancing the sealing engagement.

The configuration of the entire support clip is configured to offer abalance between support and flexibility. By varying the dimensions(mainly the wall thickness and the height), the rigidity and thecross-sectional shape along the perimeter of the clip, different levelsof support and flexibility are provided in the different sections of themask. Whilst support portion 4842 of the clip is generally perpendicularto the sealing plane SP-5, as it can be seen in FIG. 48, in someembodiments, the support portion and a perpendicular to the sealingplane may form an angle a there between. In some examples of thetechnology, the cross-sectional shape of the flexible support clip is atleast partially characterized by the angle a and/or the relative lengthof the arms of the L, C or Z shape. For example, as it will be discussedlater in relation to FIGS. 51-54, where higher softness and lowersupport is needed, such as in the sensitive area of the nasal bridge,the clip may use one, or combination of two or more of the followingfeatures: higher support portion 4842, a thinner support portion 4842 oran increased angle α. For example, angles bbetween 20° and 50°, and morespecifically bbetween 30° and 40°, may be suitable for suchapplications. Variations in the overall physical structure of the firstflexible clip, such as changing the overall shape of the clip (i.e. fromC to L-shaped) or changing the relative lengths of various sections ofthe clip (e.g. changing the relative length of cushion coupling portion4840 or support portion 4842) can also be implemented to achieve similarresults.

The cantilever springe effect resulting from the flexible nature of theclip was already described in previous paragraphs. However, the flexiblenature of the clip may define a broader self-adjustment effect that maybe distributed along the length of the clip and that goes beyond thecantilever springe effect. In particular, such an adjustment occurs whenthe mask is in an operational configuration—it is attached to the user,the headgear straps are tightened and the plenum chamber of the mask ispressurized. In this instance a certain balance is established betweenthe forces acting on the clip. For example, in a direction perpendicularto the contact plane SP-5, such forces include forces depressing theclip (such as the tension force of the headgear applied via the maskframe, the applied pressure P4 and the reaction force applied by thefoam cushion) and the clip's spring constant, defined mainly by thesupporting portion 4842. However, the applied pressure in the plenumchamber acts not only in the direction indicated as P1, but on theentire inner surface of the clip. The overall balance of forces and theflexibility of the clip may lead to a dynamic change in the entireconfiguration of the cross-sectional profile of the clip, once the maskis in its operational configuration. Thus, the shape of the clip (suchas the generally L shape shown in FIG. 48) may undergo changes, whichmay be different in the different peripheral sections of the clip. Someof the changes may include any one of the following: inwardly oroutwardly directed bending in any section of the supporting portion4842, modification of the angle between the portions 4840 and 4842 (notshown in FIG. 48, but being complimentary to angle a) and change of theangle of inclination of the cushion supporting portion 4840. An inwardrotation of the cushion coupling portion 4840 (the cushion supportingsurface) towards the plenum chamber defines a roll-in effect for thecushion. The changes may vary along the periphery of the clip. Forexample, in some sections around the periphery of the clip, the surfaceof the clip at cushion coupling portion 4840 (and therefore the cushion)may roll-in, whilst in others, they may roll-out.

The direction and the extent of modification of the configuration of theclip will depend on the above discussed balance of forces, on thepatient's face profile and on the material properties of the clip, suchas its rigidity/flexibility. These characteristics may be modified byway of changing the clip's shape, dimensions (e.g., thickness and/orheight) and/or material properties. The specific dimensions and material(more specifically the mechanical) properties of at least someembodiments of the clip that facilitate such a modification of thecross-sectional profile of the clip, when in use, are described furtherin the text. The modification represents a self-adjustment mechanismthat allows the flexible clip and the attached foam cushion toaccommodate a wide variety of face geometries and features and providecomfortable and reliable seal. The effect of such a self-adjustmentmechanism may be further enhanced by a purposeful change of themechanical properties and the general spatial relationship (or angle)between the portions 4840 and 4842 around the periphery of the flexibleclip, as will be discussed in relation to FIGS. 51-54.

In some instances, the support portion 4842 of the clip may be chosen tohave dimensions (height and thickness) and mechanical properties (i.e.,flexibility) that would allow the air pressure to create an air springeffect. This is to say that, as shown in FIG. 48, because of theflexibility of the supporting clip, the pressure P4 in the plenumchamber may be used to assist the overall sealing of the mask cushion bydepressing the foam cushion towards the patient's face. As pressureincreases, so does the force creating the seal. The spring effect mayalso vary around the periphery of the clip.

All of the effects described in the previous paragraphs allow theflexible clip to compliment the flexibility of the supporting clip.Their effect, however, is limited by the rigidity of the clip. The clipmeeds to have sufficient overall rigidity in order to providesignificant structural support to the foam.

In some specific embodiments, if for any reason a substantial complianceand softness is required, the dimensions and the material properties ofthe clip may be selected so as to enable the clip to at least partiallyexpand in a balloon like manner, under the pressure applied to the maskwhen in use. Such an arrangement will exhibit increased compliance, butreduced stability.

In the example shown in FIG. 49, the soft/flexible first clip has avarying cross section from the bridge of the nose to the bottom of themouth, and is symmetric through the center plane. The geometry of theflexible clip will largely be affected by the overall design of the foamand the specification of the clip material. For one particularembodiment, the thickness of the flexible clip in both the couplingportion 4840 and support portion 4842 may vary between about 1 mm to 2mm. However, other thicknesses may be implemented.

A location ridge 4845 shown in FIG. 48 and in FIG. 50 may be included onan external periphery of the surface of the flexible clip that contactsthe foam. This structure may then aid alignment in the manufacturingprocess of the foam to the foam mounting surface provided by thecoupling portion 4840 of the flexible clip. The location ridge isdesigned to be small and does not come into contact with the user'sface. For example, it may be about 0.5 mm in height and width with afull round on the top. Other heights may be chosen and may be in a rangeof about 0.2 mm to 2 mm.

5.4.2.3.1 First Clip Regions

The first clip may be implemented with different characteristics indifferent regions of the clip. For example, different cross sectionalgeometries and/or properties in the various portions of the clip isintended to impart different properties to the associated sections ofthe mask and allow efficient sealing with the respective regions of theuser's face, as described in detail below. Example regions areillustrated in FIG. 49. The regions may include a nasal bridge regionFC-NBR, a sides of nose region FC-SNR, a sides of mouth region FC-SMRand a bottom of mouth region FC-BMR.

(a) Nasal Bridge Region—FIG. 51

The example of the cross sectional geometry in this region shown in FIG.51 may be ‘C’ shaped and allows the foam cushion to move substantiallyperpendicularly to the user's face to accommodate a wide range of nasalbridge depth. It may be the softest/most flexible part of the first clipand have a thickness in its support portion 4842 of about 1 mm. However,this thickness in some versions may be in a range of about 0.25 mm-1.5mm. The movement is generated by the angle between the inner face (inthis case 45°) (with a range 0° to 90°) and the overall size of the ‘C’section.

The surface that attaches to the foam at cushion coupling portion 4848may be the largest in this area (e.g., about 15 mm) but can be in arange of about 10 mm-25 mm. This sizing is done to reduce the likelihoodof the seal blowing out on the sides of the nose, since it restricts theoutward movement of the flexible clip in this region.

The height of the clip measured, as indicated in FIG. 51, from theboundary of the area used to attach the flexible clip to the rigid clip,to the boundary of the area used for attachment to the foam, isindicated as 13 mm. However this may vary bbetween 10 and 20 mm. For anindicated thickness of the clip of about 0.25 mm to 1.5 mm, this willdefine a height to thickness ratio of bbetween 5 and 80.

The combination of these values may define the overall sealing andcomfort quality.

(b) Sides of Nose Region—FIG. 52

The example cross sectional shape of the first clip in this region shownin FIG. 52 may also be ‘C’ shaped and may allow the foam to pivot andmatch the facial geometry at the sides of the user's nose. This allowsthe foam contact surface to be parallel with the user's nose. Theflexible clip support portion 4842 in this region of the flexible clipmay have a thickness of about 1 mm. However, this thickness in someversions may be in a range of about 0.25 mm to 1.5 mm. The height ofabout 12 mm gives the range of movement necessary to conform to theuser's nose. However, this height in some versions may be in a range ofabout 8 mm to 20 mm.

The height of the clip is measured, as indicated in FIG. 52, from theboundary of the area used to attach the flexible clip to the rigid clip,to the boundary of the area used for attaching the clip to the foamcushion. The above noted thickness and height of this section of theperiphery of the clip define a height to thickness ratio of bbetween 5and 80.

(c) Sides of Mouth Region—FIG. 53

The example clip cross sectional geometry illustrated in FIG. 53 at theregion on both sides of the mouth may be ‘L’ shaped and can be the mostrigid portion of the clip, effectively forming an anchor point aroundthe sides of the mouth. The support portion and the cushion couplingportion can also be angled with respect to each other for increasedstability and better sealing. The more rigid configuration is suitablesince these side of mouth regions of the face are deemed to be the leastpressure sensitive. Furthermore this angled configuration allows thefoam to be pivoted into the user's face to allow for varying facialprofiles. The flexible clip and more particularly its support portion4842, can have a thickness of about 2 mm but other thickness in a rangeof about 1.5 mm to 3 mm) may also be implemented to provide the increasein stiffness. In some versions, a ‘C’ shaped geometry may also beimplemented for these regions of the flexible clip. However, this mayresult in an increase in overall mask footprint.

The height of the clip measured, as indicated in FIG. 53, from theboundary of the area used to attach the flexible clip to the rigid clip,to the boundary of the area used for attachment to the foam cushion, isindicated as 15 mm. However this may vary bbetween 10 and 20 mm. For anindicated thickness of the clip, this will define a height to thicknessratio for this section of the periphery of the clip of bbetween 3 and80.

(d) Bottom of Mouth Region—FIG. 54

The example clip cross sectional geometry for the bottom of the mouthregion illustrated in FIG. 54 is ‘L’ shaped and is configured to allowthe flexible clip to roll-in. This permits the foam to move upwards anddownwards relative to the face (left and right with respect to FIG. 54)and maintain a parallel top sealing surface with respect to the user'sface. This feature allows for movement of the user's jaw without losingthe cushion-to-patient seal (i.e., jaw drop during usage). The flexibleclip can have a thickness in this region of 1 mm (with a range of0.25-1.5 mm). The roll-in action is possible with the rounded innersurface RIS, this action is further aided by having a sufficiently largeradius (for example, about 4 mm, but may be any radius within a range ofabout 2 to 10 mm) that prevents the lip surface attached to the foam(the cushion coupling portion 4840) from folding inwards. The flexibleclip can have a height of about 17 mm but may be a height in a range ofabout 15 to 25 mm) in this region. This height range permits sufficientmovement of the foam cushion. The height of the clip is measured, asindicated in FIG. 54, from the boundary of the area used to attach theflexible clip to the rigid clip, to the boundary of the area used forattachment to the foam. Although an ‘L’ cross sectional geometry isillustrated, in some versions, a ‘C’ shaped geometry may be configuredin this area, but would result in an increase in overall mask footprint.

The indicated thickness and height of the clip will define a height tothickness ratio for this section of the periphery of the clip ofbbetween 10 and 100.

5.4.2.3.2 First Clip Interfacing

In some versions, the flexible clip may include a lip seal 5550, such asthe examples illustrated in FIGS. 55 and 56. The lip seal serves as aportion of the flexible clip that seals the flexible clip with the maskframe. Thus, the lip seal 5550 is used between the flexible clip and themask frame to ensure a seal is maintained between the two components.The lip seal may be part of the flexible clip and may extend around aninternal periphery of the flexible clip. The lip seal can be flexible.For example, when the flexible clip is coupled to the mask frame, suchas with the hard clip attachment features, a more rigid portion of themask frame may be depressed against the more flexible lip seal to createa tight/effective seal between them. This may result in some movement ordisplacement of the more flexible lip seal 5550. In otherconfigurations, the lip seal 5550 may be part not of the first supportclip 3812 (e.g., flexible clip), but of the rigid second clip 3814 orthe frame 3816.

The interfacing between the second clip (or more rigid clip) and themask frame is also shown in FIGS. 55 and 56. The rigid clip can serve asa hard stop 5551 to prevent the cushion assembly with the flexible clipfrom being pushed too far into the mask frame. Thus, the rigid clip mayassist with ensuring proper alignment of the lip seal 5550. Anincorrectly assembled cushion could lead to leaks through the lip seal,the mask frame protruding too far and contacting the patient, move theheadgear attachments on the mask frame too far and causing contact withthe patient.

The performance characteristics (how it behaves under load, e.g.,increase/decrease in sealing force) can be altered in the individualsections of the flexible clip by modifying any one or more thefollowing: material properties, soft clip thickness, overall flexibleclip height and width and/or soft clip geometry.

5.4.2.3.3 First Clip Materials

Generally, unlike the foam cushion which may be permeable to air, thefirst clip is typically not made of foam and can itself be airimpermeable or impermeable to air. The first clip is considered“flexible” or “soft” in that it may be flexible in use or made from anelastic material that will deform under load. This includes but is notlimited to, silicone, TPE, TPU and natural rubbers.

TPE material is desirable as it has a higher potential to be adheredto/moulded to the foam and/or the rigid clip.

5.4.2.3.4 First Clip Manufacture

The manufacturing process for the flexible clip may include injectionmoulding. It may be moulded with any one or more of the followingtechniques. It may be moulded as a separate component. It may beovermoulded onto another component or components such as any one of thehard clip, mask frame and foam cushion. For example, it may be mouldedto both the foam and the hard clip.

Depending on the manufacturing process, if the flexible clip ismanufactured as a separate component, it could be assembled to the hardclip by one or more techniques. For example, it may be adhered such aswith an adhesive, glue or tape. It may be assembled by flame lamination,ultrasonic welding, injection moulding, such as a 2K or two-shotinjection molding process that employs multiple (e.g., two) differentpolymers by a single injection moulding process.

5.4.2.4 Second Clip (e.g., Hard Clip)

As illustrated in FIGS. 56 and 57, the optional second clip 3814, whichmay be more rigid with respect to the flexible clip, can allow for easyassembly and disassembly of the cushion assembly to and from the maskframe. This can permit ease of cleaning of the mask frame and for thereplacement of the cushion assembly. While different structures mayserve as the mechanism for attachment of the rigid clip to the maskframe, FIGS. 56 and 57 represent an example in which a plurality ofretaining features (e.g., snap elements 4024 or clips) lock torespective surfaces of the frame and abbutingly support the rigid clip(as well as the entire cushion assembly), to the frame. These featuresof the retention mechanism have been described with reference to FIG.40. Alternative assemblies are also possible.

Generally, the second clip 3814 allows for a harder interface betweenthe flexible clip/foam assembly and the mask frame. Whilst the use ofthe hard clip may increase usability, it is not essential for theoperation of the mask. Alternate attachment mechanisms can be used toattach the cushion assembly to the mask frame. Similarly, a maskassembly may be designed that may not necessarily include a support clipthat is not flexible. As mentioned earlier in the text, the use of alarger amount of foam will be necessary in such a case.

An alternative assembly mechanism between the foam cushion and the maskframe, some of which do not include rigid or even flexible clip, mayinclude a tongue and groove geometry between the flexible clip and themask frame.

In some versions, a portion of the flexible clip may be configured toattach to the mask frame by stretching and gripping a coupling edge ofthe mask frame. In some examples, the he flexible clip may be configuredfor coupling with the mask frame or rigid clip by an interference fitsimilar to air-tight food containers. In some versions, the flexibleclip and the mask frame may have a tongue and slot interface betweenthem and a secondary lip seal or gasket may be present to preventair/pressure leak. In some versions, the cushion assembly may bepermanently attached to the mask frame. In some versions, an adhesive,such as an adhesive tape, may be employed between the cushion assemblyand the mask frame.

The rigid second clip can provide structural integrity to the cushionassembly due to the soft/flexible nature of the flexible clip and foamcushion. The rigid clip can also allow the cushion assembly to maintainits shape even when disassembled from the mask frame.

5.4.2.4.1 Second Clip Materials

The hard clip can be made of any suitable rigid material. For example,the second clip may be made from a rigid thermoplastic material. Suchmaterials may include, for example, acrylonitrile butadiene styrene(ABS), Nylon and/or Polycarbonate.

The second clip may, for example, be manufactured by injection moulding.

5.4.3 Supra Nasal Sealing Additional Examples

Another example foam mask of the present technology may be consideredwith reference to FIGS. 69 to 86. The mask may be suitable for sealingaround the mouth and over the nose. The foam cushion 3810 is illustratedin FIG. 69. The cross section geometry of the cushion may be generallytrapezium in shape with the corners contacting the patients face roundedfor comfort. This generally trapezium shape provides stability. As shownin FIG. 70, the flat contact surface has been partially removed to forma nasal recess 6912 adapted to receive a user's nose and reduce thepressure applied by the mask to the nasal bridge area. The height of therecess (in a vertical direction parallel to the nose height) can beabout 17 mm. (See cross-section of FIG. 70.) In some versions, it canoptionally be any height up to the width of the foam, e.g. 25 mm).Moving from vertical(the direction along the length of the user's nose)to horizontal direction (the direction of the width of the user's nose),the recess gradually decreases until the recessed surface starting frompoint 6910A joins the non-recessed surface at point 6910B. The width6910C of the recess in the horizontal direction is between about 10 and35 mm, but may be about 20-25 mm. A well designed recess allows for theuser's nose to be hugged by the foam. This increases the mask stabilityin the region. An increase in the width of the recess can provideadditional relief/comfort to the user, but it will have the adverseeffect for sealing and stability. The depth of the recess is about 9 mmbut it can be in a range up to the full height of the foam, e.g., 9 mm).An increase in the depth of the recess will provide improved visibilityand additional relief/comfort to the user, but may adversely affect theoverall durability of the foam cushion.

The cross sectional geometry of the foam in the side of nose and mouthregion may be that of any of the cushion versions described in thisspecification. However, there may also be a smooth transition betweenthe new nasal bridge and side of nose regions. The recess may bemanufactured concurrently with a compression cutting process for thefoam cushion, but it can also be formed during a secondary process by,for example, additional compression cutting, thermoforming and/orgrinding.

5.4.3.1 First Clip (e.g., Flexible Clip)

Similar to the prior examples, the mask may include a first clip (e.g.,soft/flexibe clip) having cross sectional geometries that vary by regionof the clip (e.g., nasal bridge region FC-NBR, sides of nose regionFC-SNR, sides of mouth region FC-SMR and bottom of mouth region FC-BMR.)Example cross sectional geometries of each of these regions are shown inFIGS. 71, 72, 74 and 75 respectively.

A. Flexible Clip Nasal Bridge Region

The formation of a recess in the foam cushion can be complemented with areduction of the width of the flexible clip surface supporting the foamcushion in the nasal bridge region. The reduced support increases thecompliance and allows the cushion to roll-in, when a pressure isapplied, thus further improving the user's comfort in the nasal bridgearea.

The cross section shown in FIG. 71 of this region of the periphery ofthe clip is generally ‘L’ shaped and allows the foam to movesubstantially perpendicularly to the user's face to accommodate a widerange of nasal bridge depth. It forms the softest (i.e., most flexible)part of the clip and has a thickness (support portion 4842) of about 0.5mm (but may suitably be a thickness within a range of about 0.25-1.5mm). The flexibility may be manifested in the flexing of support portion4842 and the angular movement between support portion 4842 and theportion having the foam contact surface. In this example, the supportportion has a height of about 11.44 mm but may suitably be a heightwithin a range of about 8 mm-20 mm. Furthermore, the foam contactsurface may be for example about 6.5 mm in width but may be a width in arange of about of about 3-12 mm. This can permit the foam cushion tooverlap the contact surface since the foam can be wider. The unattachedportion of the foam may the flex independently from the clip. In someversions, this cross sectional portion the clip may be ‘c’ shaped, butwould result in an increase in the overall mask footprint.

B. Flexible Clip Sides of Nose Region

As seen in FIG. 73, in the side of nose region at location 7310H, thereis an increased overall height of the foam due to the supporting sectionof the clip on both sides of the nose, compared to the surroundingareas. This can provide better support and improve seal in this specificregion.

The cross section of the clip in this region of the mask as shown inFIG. 72 is generally ‘L’ shaped and allows the foam to more easily pivotand match the facial geometry at the sides of the user's nose. Thegeometry allows the foam contact surface to be parallel to the user'snose. The flexible clip at the support portion 4842 may have a thicknessin this region of about 0.75 mm but may be a thickness in a range ofabout 0.25-1.5 mm.

The height of about 9.46 mm (but may suitably be a height in a range ofabout 8 mm-20 mm) can give a range of movement necessary to conform tothe user's nose. Such a localized increased height in this region allowsfor, without changing the shape or the thickness of the foam in thisregion, additional sealing force to be applied to form a better sealaround this critical region.

Alternatively, or in addition by combination, to the increased clipheight, a similar effect can be achieved through a localised increase atlocation 7310H in height of the foam cushion in the region of the clipof FIG. 73.

Optionally, a ‘c’ shaped geometry may be implemented in this region, butwould result in an increase in overall mask footprint.

C. Flexible Clip Sides of Mouth Region

A cross-sectional geometry as indicated in FIG. 74 may be implemented inthe sides of mouth region. The region can be configured to have an angleβ between a horizontal that is perpendicular to an axis of thesupporting portion 4842 and the foam contact surface supporting the foamcushion. This angling permits a roll-in of the foam contact surfaceinwardly to better hug this region of the face when the foam cushion isapplied. It can also improve the overall stability of the system.

This clip cross sectional geometry on both sides of the mouth shown inFIG. 74 is generally ‘L’ shaped. The large angle β reduces the inwardflexing range of the clip and enhances the rigidity of the clip. Thisallows this section of the mask to better hug the face, effectivelyforming an anchor point around the sides of the mouth. The rigidity ofthe flexible clip may be at its highest in this region. Such decreasedflexibility in this region of the face may be suitable since it is theleast pressure sensitive region of a user. The cross geometry alsoallows the foam to be pivoted into the user's face to allow for varyingfacial profiles. The flexible clip and more particularly its supportportion 4842, can have a thickness of about 1.2 mm (but may be asuitable thickness in a range of about 1 mm to 2 mm) to provide thedesired stiffness. The angle β can be about 37.1 degrees (but may be asuitable angle in a range of about 20-60 degrees).

Optionally, a ‘c’ shaped geometry design could be used in this area, butwould result in an increase in overall mask footprint.

D. Flexible Clip Bottom of Mouth Region

The clip cross sectional geometry shown in FIG. 75 for the bottom of themouth region is generally ‘L’ shaped and allows for the flexible clip toroll. The small (close to zero) angle β allows the foam supportingsurface to flex. This allows the foam to move upwards and downwardsrelative to the face (left and right with respect to the illustration ofFIG. 75) whilst maintaining a parallel top sealing surface with respectto the user's face. This feature allows for movement of the user's jawwithout a loss in seal (e.g., jaw drop during usage). The flexible clipcan have a thickness of 0.75 mm (but can suitably have a thickness in arange of about 0.25 mm-1.5 mm). The roll-in action is aided by thesmooth rounded internal surface RIS and a height of about 14.21 mm (butmay have a suitable height in a range of about 12-25 mm).

Optionally, a ‘c’ shaped geometry could be implemented in this region,but would result in an increase in overall mask footprint.

5.4.3.2 Second Clip (e.g., Rigid Clip)

Similar to the other versions, the flexible clip as shown in FIG. 76 hasa lip seal 5550 that, when the flexible clip is attached to the hardclip, overhangs an edge 7660 of the hard clip (e.g., second clip 3814).The overhanging engagement is such that this peripheral lip sealsagainst the hard clip edge. The angle G the lip seal makes to thehorizontal is can be small (e.g., about 5 degrees (with a suitable anglerange of about 0 to 20 degrees). This ensures that, when the frame isassembled to the cushion, the lip seal will always be under tension asit is depressed against a more rigid mask frame portion 7662, whichimproves the sealing engagement and minimizes the change of potentialbuckling in the lip seal.

The engagement of the soft and hard clips is such that an engagement rib7664 of the hard clip is received in an engagement groove 7666 of themask frame. There are a number of points along the engagement groovewhere stop points 7668 are formed to limit the insertion of theengagement rib into the groove. The hard stop can be a continuous ridgeor a set of points localized to a number of positions (e.g., 6) aboutthe periphery of the frame. They can be arranged such that, when theclips are in the engaged configuration, the engagement rib abuts againstsome or all of these stop points and is prevented from entering theengagement groove any further. Apart from limiting the insertion in avertical direction, the hard stop points may also constrain thehorizontal movement of the frame to cushion assembly. This is achievedby at least one, preferably several, of the hard stop points having arecess that receives the engagement rib. As the width of the opening isarranged to tightly receive the rib 7664, the arrangement limits themovement of the clips in horizontal direction.

As seen in FIGS. 77 to 82, a top attachment snap element 8010-1 can beengaged to the respective frame opening 8012. One way is to pivot theentire clip assembly so that the snap element 8010-1 at a top lockingedge of the clip is pivotably inserted in the respective frame opening8012. This requires minimal effort on behalf of the user. The entireclip assembly is then pivoted back to be parallel to the frame and thelower part of the clip/cushion is depressed against the frame until thebottom snap element 8010-2 clicks into engagement with the respectiveframe engagement portion. Alternatively, the entire clip assembly may bealigned in parallel and depressed against the frame until both the topand the bottom snap elements of the clip assembly engage with the frame.The engagement of the top attachment in this case requires a slightlylarger force which is arranged to be approximately equal to the topheadgear tension. Because of that, in the event the top attachment hasnot been fully engaged during assembly, it will self-engage as the userputs on the mask.

The bottom snap element 8010-2 forms the main interface the user willmanipulate during disassembly, and it is sized so a finger cancomfortably operate the mechanism. As best seen in FIG. 81, the bottomsnap element 8010-2 on the hard clip has two rounds leading to taperedges which increases usability as that will act as lead ins to thecorresponding receiving slot 8014 on the mask frame.

In this version, the engagement mechanism (receiving slot 8014) in theframe does not run fully across the bottom, this is specificallydesigned so during disassembly the user can slide their finger downwardswhile maintaining full contact with the hard clip.

5.4.3.3 Foam Mask Assembly Operation

Operation/performance of the example masks may be considered inreference to FIGS. 83 to 86. The performance areas around the peripheryof the cushion assembly of FIG. 83 include nasal bridge region ZA, Sidesof nose region ZB, upper cheek region ZC, sides of mouth region ZD andbottom of mouth region ZE. The design intent of the cushion in terms ofhow it reacts to a user's face is further described herein.

The cushion is configured to apply a different amount of load orreaction force to individual regions of a user's face. The nasal bridgeregion ZA is the least loaded as it is the most sensitive region. Thenthere is an increase in loading in regions ZB and ZC as a more robustseal in this region would decrease the likelihood of leak into theuser's eye. In comparison, region ZD and ZE is the most heavily loadedand acts to anchor the cushion to a user's face. There may be uniformloading across regions ZD and ZE, but this can change due to individualuser's facial profile.

The cushion has a pivoting motion as the top and bottom headgear strapsare tightened or loosened. The approximate pivot axis is shown with thearrow of FIG. 84. By tightening the top head gear straps regions ZA, ZBand ZC pivot into the user's face, and region ZD) and ZE pivot away.When the bottom straps are tightened region ZA, ZB and ZC pivot awayfrom the user's face and region ZD and ZE pivot into the user's face.The inverse will happen with the loosening of the top and bottomheadgear straps.

FIG. 85 provides an approximate indication of the relativepressure/reaction force in the various respective regions of the mask.The arrows indicate the pressure/force applied by the mask to the user'sface, when the headgear is tensioned to support the mask on the user'sface. The different sizes of the arrows indicate the relative pressuredifferences in each respective region. Thus, the mask may be configured(for example by virtue of the characteristics of the clip(s) and/or foamcushion) to apply different reaction forces in different regions of itspatient contact surfaces. In the illustrated example of FIG. 85, themask is configured for smaller forces to be applied in the upper regionsof the mask (e.g. the sensitive nasal bridge region ZA, sides of noseregion ZB and/or upper cheek region ZC). The mask may be configured forgreater forces to be applied in lower regions of the mask (e.g., sidesof mouth region ZD and/or bottom of mouth region ZE). In this example,the mask is configured for the smallest force at the nasal bridge regionZA. These forces may typically be symmetric from side to side of theimage of FIG. 85 (e.g., approximately the same on the left side as theright side in the respective regions). Other forcedistributions/variations may also be applied.

As discussed earlier in the text, the cushion may also exhibit a roll-ineffect as it is applied to the user's face. As region ZA is depressed bythe user's nose bridge, region ZB can roll into the sides of the user'snose, which acts to increase the compliance of the cushion's seal to theuser's face. As region ZE is depressed by the user's chin, region ZDrolls into the sides of the user's mouth, forming a more effectiveanchor as it wraps around the user's face.

FIG. 86 shows approximate roll-in response in the respective regions ofthe mask. The arrows indicate the relative extent of the roll-inresponse when the headgear is tensioned to support the mask on theuser's face. The difference in size of the arrows indicates the relativedifference in roll-in in each respective region.

Thus, the mask may be configured (for example by virtue of thecharacteristics of the clip(s) and/or foam cushion) with differentdegrees of roll-in in different regions of its patient contact surfaces.In the illustrated example of FIG. 85, the mask is configured forgreatest degrees of roll-in to be applied in the sides of nose region ZBand/or sides of mouth region ZD, which may be approximately the same.The mask may be configured for smaller degrees of roll-in to be appliedin other regions (e.g., nasal bridge region ZA, upper cheek region ZCand/or bottom of mouth region ZE) which may be approximately the same.These roll-in forces may typically be symmetric from side to side of theimage of FIG. 85 (e.g., approximately the same on the left side as theright side in the respective regions) However, other force variationsmay also be configured.

The degree of roll has been intentionally modified to assist with thecomfort and with the efficient sealing of the mask. There are a numberof ways to achieve a specific degree of rolling.

Generally, around the periphery of the cushion interface, the plane onwhich the foam cushion sits, may be angled inwardly to the users face atdifferent angles in a manner to promote degrees of roll-in. Some areas(such as sides of mouth) have a more significant angle in order tofacilitate a greater roll-in affect.

The flexibility of the soft (e.g. TPE/Silicone) clip to which the foamcushion is assembled is, broadly, shaped as a right angle beam, henceallowing for inward roll (intended via the inwards angling as describedabove).

The flexible clip material is selected to be flexible and compliantwhich can also allow for inwards roll (per the intention anddescriptions above).

The degree of support to the foam provided by the underlying flexibleclip surface can be changed by ensuring that the supporting surface ofthe flexible clip extends only partially under the foam surface. Thus,some of the foam surface, usually on the inner side of the mask, can beunsupported (i.e., the foam overhangs the flexible clip). When pressureis applied to the foam, the unsupported surfaces may give-in andfacilitate the roll-in effect.

Thus, in some examples, the foam cushion assembly can have parametersthat vary in at least some sections of the periphery of the clip and/orassembly, such as:

-   -   Spring constant of the clip and/or the foam cushion;    -   Cross-sectional profile of the clip and/or the foam cushion;    -   wall thickness of the clip;    -   The angle of the contact surface to which the cushion is        attached;    -   The overhanging of the cushion with respect to the supporting        contact surface; and/or Foam thickness.

5.4.4 Further Optional Foam Mask Features

As previously described, masks may be implemented with a foam cushionwhether they are above or below the nose masks as previously describedor even nasal only masks. Generally it is desirable to achieve a maskwith maximum comfort and compliance/seal performance. Various foam sealforming cushions configurations may be configured to achieve thisdesire. However, when designing a comfortable foam cushion, there areother trade-offs to consider. One such trade-off is permeability, whichis closely associated with the foam's softness and compliance. Forachieving desired seal and comfort, a relatively thick layer of foam onthe mask can be implemented. Apart from being more heavy and obtrusive,a large layer or foam, even of limited permeability, could be associatedwith an increased leak and compromise the provided pressure therapy. Toaddress the issues with size and permeability, some versions of thepresent technology as previously mentioned can employ a flexibleintermediary structural component (e.g., clip(s)) between the foam layerand the frame. Such a structure, such as the above described flexibleclip(s), attaches to the foam seal forming layer. The balance ofrigidity and flexibility of such an intermediary structure (e.g., aflexible clip) can be chosen so that it can serve as a substitute forsome of the foam cushion. Thus, a less bulky foam layer can be used. Inaddition, the clip is generally formed of a non-permeable material.Because of that, and because of the specific concave configurations,discussed earlier in the text, a portion of the clip covers at least aportion of the foam cushion and may reduce the overall leak associatedwith the foam cushion. The flexible clip may then maintain the benefitsof support and compliance, while minimising leak. Some additionaloptional features of the intermediary structure(s) may be consideredwith respect to achieving some of the goals of the previously describedflexible clips.

5.4.4.1

Clip Flexibility

One disadvantage of simply providing a foam seal forming layer to a hardclip or a frame/shell of a mask is that it has a risk of bottoming outon the hard/rigid portion. Bottoming out occurs when the foam iscompressed to such a degree that the patient starts to feel the rigidityor hardness of the underlying clip or frame/shell of the mask. Toaddress this issue, some examples described throughout thisspecification introduce a soft/flexible clip that flexes under pressureapplied to the mask. The arrangement is such that the flexibility andthe compliance of the flexible clip compliments that of the foam layerto improve the overall compliance of the mask.

However, the flexibility nature of these flexible clips need notnecessarily be a consequence of particularly flexible materials. Forexample, the function of the flexible clip may be achieved with asemi-rigid or even rigid clip or mask frame/shell instead to which thefoam is applied. In such cases, the flexible response may be introducedby structural features, such as locally thinned or profiled sections,that may form a hinge or gusset on a rigid clip or frame to which thefoam is attached. Thus, the foam seal forming layer may be directlyattached to a rigid clip that has been designed to have flexiblesections with structurally introduced compliance in locations wherecompliance is needed. Thus, the flexible support clip may be formed by arigid material and the flexibility may be induced by way of introducingone or more compliance regions, such as by introducing one or more linesof weakness or one or more regions of weakness.

Two different examples of such a configuration are illustrated withrespect to FIGS. 58A and 58B. FIG. 58B shows a cross section of the foamcushion assembly of FIG. 58A with a foam cushion 3810 and a rigid clip5858. The rigid clip 5858 may then attach to a frame (not shown in FIG.58). This rigid clip 5858 is flexible in that it has structural featuresdesigned to promote flexing. As shown in FIG. 58B, the wall of the clipincludes a profile to implement a gusset at 5859-A, but the thickness ofthe wall has not been changed. The other example shown at 5859-Bintroduces one or more lines of weakness around the periphery of theclip, where the wall is thinner. Each line can be a continuous line oran interrupted one, e.g., a series of weak spots. In such cases, theresult can be an increased level of flexibility of wall of the rigid orsemi-rigid clip or frame. These structural features can also beimplemented to modify the flexibility and the spring constant of analready flexible clip such as any of the clips described throughout thisspecification.

Another example for imparting flexibility into an otherwise rigid orsemi-rigid mask plenum chamber can be to implement flexing sectionsdefined in the recessed rigid clip 6758 or mask shell. For example, sucha rigid clip coupled to a foam cushion 3810 is illustrated in FIGS. 67and 68. As illustrated, the frame/clip can have one or more regions ofweakness introduced by having portions of rigid material removed at oneor more clip recess(es) 6770. This allows the rigid clip/shell tocompress easier under load. Thus, these recess sections can bepositioned at regions of discomfort (such as near the nasal bridge orsides of the nose) where more flexibility or compliance is needed. Therecesses may be filled with another flexible (but impermeable) materialsuch as a recess membrane 6772 made of, for example, silicone or TPE.Alternatively, the recesses created by the removed sections may becovered by a single flexible sheet. Such a sheet may, for examplerepresent a silicone membrane attached to the inside of the rigid clip.

5.4.4.2 Clip Alternatives

In various assemblies described herein, a clip is described as anintermediary structure for applying foam to a mask frame. For example,the foam mask design has been described as having a foam seal forminglayer, attached to a flexible clip that is subsequently attached to ahard clip. The hard clip is removably attachable to the mask frame. Theframe in this case may be a rigid part of the mask that provides somelevel of shape and support to the mask structure and allows for headgeartension to be transferred to the seal forming portion to seal on theface.

Another configuration of a foam mask may include a flexible shell orchamber made from a flexible material (such as TPE or Silicone). Such anassembly may be considered with reference to FIGS. 61, 60 and 60. Aflexible chamber or shell 6160 can serve, in part, as the flexible clip,where the flexibility of the shell provides compliance when pressure isapplied to the mask. In this case, a headgear frame 6162, which mayinclude a shell aperture 6163, is fit over the shell 6160 as a separateremovable structure made of a rigid material to provide support. Whilstthe concave silicone chamber of the shell 6160 can serve in part as theC-shaped flexible clip, one substantial difference is that the flexibleshell also more completely forms a part of the mask chamber or plenumchamber 3200. For example, it may optionally include a connection port3600 for coupling with a gas delivery conduit or circuit 4170 and/or avent 3400.

Although FIG. 60 shows the shell 6160 version of the clip attached tothe foam cushion, in some cases a further intermediary may beimplemented such as the examples illustrated in FIGS. 63A, 63B and 59.These versions of the mask assembly implement a foam cushion attacheddirectly to a rigid clip 6314. The rigid clip 6314 may then couple withthe shell 6160 or other mask frame with engagement features 6319. Thefoam may be semipermeable, which is correlated to its softness andbreathability. However, a permeable foam layer will leak air and airpressure.

In this case, the shell 6160 or other mask frame, can include anadditional flexible member 6320 peripherally positioned inside the maskplenum chamber and configured to cover at least a portion of the foamcushion when the rigid clip is assembled/coupled to the shell or maskframe as shown in FIG. 63B. This flexible member 6320 can be an airimpermeable skirt, flap or layer positioned within the mask chamber thatmoves to engage and cover the inner surface of the foam cushion.

The flexible member 6320 may be a flexible membrane made of, forexample, TPE or silicone and may be attached to the chamber formingwalls of the mask shell/frame, or to a rigid clip 6314 attached to themask shell/frame. This flexible membrane forms a flap that is adaptedto, at least when under pressure, interact with the foam and cover atleast partially the under-surface of the foam layer when pressure isapplied to the mask. Preferably, the flap will not interact with theface of the patient. The implementation of such a non-permeable layerenhances the overall quality of the seal, which otherwise may be atleast partially compromised by the at least partially permeable foamlayer.

This sealing layer (flexible member 6320) can also enhance theair-spring effect within the chamber. As the foam sealing portionoverhangs off the edge of the hard clip or frame to which it isattached, any force applied to the flap also acts on the foam sealingportion. Having the non-permeable flexible flap cover the foamunder-surface (plenum chamber side of foam), will allow for pressure tobuild up and push the foam into a better sealing engagement whenpressure from a flow generator is applied to the mask chamber.

A variation of the flexible member 6320 is seen further in FIG. 59. Inthis version, flexible member more completely covers the foam cushion byextending internally beyond the supporting surface of the underlyingrigid clip. As such, it also extends to at least partially cover theinner lateral surface of the foam cushion. In this position it may bemore affected by the flow through the mask from the flow generator so asto move as illustrated in FIG. 59. The length of the flap may beselected on the basis of how thick the foam layer is and whether contactof the flap with the face is desirable. Thus, it may extend to contactthe face in some versions and not in others. Such a membrane may beapplied to any of the mask described in this specification to reducefoam air leak (i.e, leak through the foam seal forming layer).

As a general requirement, the contours on the foam layer should maximisecomfort and effect a seal by matching a patient's facial profile orfacial contour. Thus, the foam seal forming layers may preferably beconfigured into a desired 3-dimensional (3-D) or desired facial profile.

In one example, the flexible clip is moulded to the desired 3-D shape orfacial profile so as to impart this shape to a generally flat foam sealforming layer when it is attached to the foam. Alternatively, a 3-Dshaped hard clip can impart 3D shape (e.g., a facial contour) to theflexible clip and the foam sealing layer attached to it.

FIGS. 64, 65, 66A and 66B illustrate additional mask examples that showalternative methods to give the foam a desired shape. One such exampleis to provide one or more rigid over clips that squeeze or clamp thefoam cushion into a desired three-dimensional (3D) profile such as whensnapped or snap fit into a foam support component such as a mask frame3816 or shell with snap elements. For example, it has been shown that afoam seal forming layer with a rounded seal forming surface isdesirable. Thus, as shown in FIGS. 64, 65, 66A and 66B, multiple clips(e.g., two separate over clips 6470-1, 6470-2) such as an innerperipheral clip (clip 6470-1 and outer peripheral clip (clip 6470-2),can depress or clamp the opposing peripheral edges/sides of a foam body,to effectively round the patient contacting edges of the foam layer.Alternatively, only one of the illustrated clips can be used or the twoclips can be arranged in a single clip.

As shown in the example of FIG. 65, the clip 6470 may have one or moreover-clip portions 6580 to squash not only the edges, but also one ormore top or internal portions of the foam layer toward the mask frame3816, shell or other mask assembly structure. For example, asillustrated in FIG. 65 at the nasal bridge and in the middle of thelower lip area optional slits 6582 partially through the top sideportion of the foam serve as channels for the clip 6470. As a result,the foam may bulge is certain portions and be pressed down in otherportions of the mask. This may enhance the compliance and/or comfort ofthe foam seal forming layer.

Alternatively, one or more of the illustrated over-clip portions canhave a 3-D shape (e.g., facial contour), which can provide the sameeffect (allow the foam to bulge in certain areas and press the foam downin other areas).

5.4.5 Further Foam Cushion Characteristics

Although the cushions described for masks herein may be implemented withmany different foam materials, foams with certain performance propertiesmay be particularly well suited when implemented for respiratorytreatments given the critical need to promote patient compliance and toensure effective delivery of medical treatments. In this regard,particularly suitable foams may be characterized by any one or more ofits permeability (Liters/min), indentation hardness (Newtons (N)),compression stress strain (Kilo-pascals (Kpa)), density (kilograms permeters³ (kg/m³)), dynamic coefficient of friction (calculated friction(cf)), compression set (percent (%)), tensile strength (Megapascal(Mpa)), elongation @ break (Percent (%)) and/or tear strength(Newtons/millimeter (N/mm)).

5.4.5.1 Permeability

For example, the foam cushion may be configured to have a particularpermeability characteristic. The permeability characteristic of the foammay be a measure of the rate of air flowing through a given sample inLiters/minute. Such permeability may be determined by the followingpermeability test. A test piece can be cut from a piece of foam with adie or a sharp knife into an annular shape (i.e., a ring-shapedgeometric foam sample or square sectioned toroid). The test piece is cutnominal to the cell rise direction from a foam sample manufactured atleast 72 hours prior. The ring has a height of 25 mm (plus or minus 1.0mm) from the bottom of the ring to the top in the cell rise direction.The inner open cylinder of the foam ring has that height and a diameterof 70 mm (plus or minus 1.0 mm). The outer edge of the foam ring has adiameter of 110 mm (plus or minus 1.0 mm). Test pieces are free fromskin voids and densification lines. The test piece will be in goodcondition without any visible defects such as burrs, delaminating, tearsetc. The test then measures the air flow through the annulus of the foamring having its constant cross section. The circular shape ensures thepressure is evenly distributed and the foam inflates uniformly. The foamtest ring is conditioned, undeflected and undistorted, for at leastsixteen hours in an atmosphere of temperature at 23±2° C. and relativehumidity at 50±5% prior to testing. The ring may be compressed betweenplates in a manner to reduce the height of the ring from 25 mm to 17.5mm during flow testing. A constant air pressure of 20 cmH2O, such asfrom a flow generator, is applied to the center of the foam ring. Airflow through the ring from the center outward across the foam is thenmeasured with a flow meter in liters/minute. Foam cushions suitable forthe present technology may have a permeability characteristic in a rangeof about 0 to 20 L/m and may preferably have a permeabilitycharacteristic in a range of about 0 to 3 L/m.

5.4.5.2 Indentation Hardness

The foam cushion may be configured to have a particular indentationhardness (IDF) characteristic. This characteristic relates to thefirmness or stiffness of the material. This characteristic has asignificant correlation to comfort, seal and stability needs. Generally,the lower the IDF—the softer the material. Testing may be in generalaccordance with BS EN ISO 2439: 2008 (method C)—determination of 40%indentation hardness check by compression of samples by 40% of itsthickness and recoding the maximum force (N). Foam cushions suitable forthe present technology may have an indentation hardness (IDF)characteristic in a range of about 110.48 to 303.11 N, and maypreferably have an indentation hardness (IDF) characteristic in a rangeof about 122.76 to 275.55 N, and still further may more preferably havean indentation hardness (IDF) characteristic in a range of about143.1-198.88 N.

5.4.5.3 Compression Stress Strain

The foam cushion may be configured to have a particular compressionstress strain characteristic. This characteristic relates to how thefoam material deflects under stress or load. This characteristic has asignificant correlation to comfort, seal and stability needs. Thecompression stress-strain may be determined in accordance with BS EN ISO3386: 1997+A1:210. The test speed may be 100 mm/minute. Stress at acompression of 40% may be calculated. Foam cushions suitable for thepresent technology may have a compression stress-strain characteristicin a range of about 2.32 to 7.26 Kpa, and may preferably have acompression stress-strain characteristic in a range of about 2.574 to6.6 Kpa, and still further may more preferably have a compressionstress-strain characteristic in a range of about 3.15 to 4.29 Kpa.

5.4.5.4 Apparent Density

The foam cushion may be configured to have a particular densitycharacteristic. This characteristic relates to the weight, firmness,“plushness” or tactile “feel” of the material. This characteristic has asignificant correlation to comfort, seal and stability needs. Theapparent density may be determined in accordance with BS EN ISO845:2009. Using measured dimensions (mm) and the weight (g) the density(kg/m³) can be calculated. Foam cushions suitable for the presenttechnology may have a density characteristic in a range of about 24.3 to117.85 kg/m³, and may preferably have a density characteristic in arange of about 27 to 107.14 kg/m³, and still further may more preferablyhave a density characteristic in a range of about 50.76 to 66.11 kg/m³.

5.4.5.5 Dynamic Coefficient of Friction

The foam cushion may be configured to have a particular dynamiccoefficient of friction characteristic. This characteristic relates tocomfort on face and perception of comfort in the hand. Thischaracteristic has a significant correlation to the surface feel ortexture of the material. This characteristic has a moderate correlationto seal and stability as a result of relationship between the patient'sskin and surface finish of the material. The dynamic coefficient offriction may be determined in accordance with BS EN ISO 8295:2004. Testpieces may be tested under a load of 1.96 N and a speed of 30 mm/minuteon a glass substrate at a temperature of 37 C to 39 C. Force readingsmay be measured and friction calculated. Foam cushions suitable for thepresent technology may have a dynamic coefficient of frictioncharacteristic in a range of about 1.86 to 19.12 CF, and may preferablyhave a dynamic coefficient of friction characteristic in a range ofabout 2.07 to 17.38 CF, and still further may more preferably have adynamic coefficient of friction characteristic in a range of about 2.43to 2.97 CF.

5.4.5.6 Compression Set

The foam cushion may be configured to have a particular compression setcharacteristic. This characteristic relates to the ability of the foamto recover to its original state post compression and conditioning. Ifthe foam has high/poor compression set it will no longer act as adynamic seal. If the foam has no compression set, coupled with a strongresilience to deterioration, it will be useable for a long period. Thecompression set may be determined in accordance with BS EN ISO1856:20019. Test spacers may be selected to give a compression ofnominally 50% and 75% to each specimen. Compression may occur for aperiod of time (e.g., 22 hours) at certain temperature and relativehumidity (e.g., 22 hours at 23 C (plus or minus 2 C) and 10% R.H.; and22 hours at 70 C (plus or minus 1C). After unclamping the testspecimens, they may be allowed to recover for 30 minutes at 23 C (plusor minus 2C) before being re-measured and the compression set % beingcalculated. Foam cushions suitable for the present technology may have acompression set characteristic in a range of about 0.16 to 17.3%, andmay preferably have a compression set characteristic in a range of about0.18 to 15.73%, and still further may more preferably have a compressionset characteristic in a range of about 3.06 to 4.4%.

5.4.5.7 Tensile Strength

The foam cushion may be configured to have a particular tensile strengthcharacteristic. This characteristic relates to the force required tobreak the foam. This has a moderate correlation to stability and seal.If the cushion has poor tensile strength, it will fail causing leak andpoor stability. The tensile strength may be determined in accordancewith BS EN ISO 1798:2008 at a tensile test speed of 500 mm/minute. Loadmay be recorded and the elongation may be determined by laserextensometry. Foam cushions suitable for the present technology may havea tensile strength characteristic in a range of about 0.03 to 0.27 Mpa,and may preferably have a tensile strength characteristic in a range ofabout 0.036 to 0.242 Mpa, and still further may more preferably have atensile strength characteristic in a range of about 0.117 to 0.143 Mpa.

5.4.5.8 Elongation @ Break

The foam cushion may be configured to have a particular elongation @(at) break characteristic. This characteristic relates the foams abilityto elongate before failing. This characteristic has a moderatecorrelation to stability and seal, as per tensile strength. Foamcushions suitable for the present technology may have an elongation @break characteristic in a range of about 72.9 to 369.05%, and maypreferably have a elongation @ break characteristic in a range of about81 to 335.5%, and still further may more preferably have a elongation @break characteristic in a range of about 243 to 335.5%.

5.4.5.9 Tear Strength

The foam cushion may be configured to have a particular tear strengthcharacteristic. This characteristic relates to the foams ability toresist tear under tension. There is a moderate correlation of thischaracteristic to stability and seal, as per tensile strength andelongation at break. The tear strength may be determined in accordancewith BS EN ISO 8067:2008 (method A) at a test speed of 50 mm/minute.Foam cushions suitable for the present technology may have a tearstrength characteristic in a range of about 0.07 to 0.69 N/mm, and maypreferably have a tear strength characteristic in a range of about 0.081to 0.627 N/mm, and still further may more preferably have a tearstrength characteristic in a range of about 0.225 to 0.297 N/mm.

5.4.6 Further Clip Characteristics

Although the cushion assembly with the clip(s) described for masksherein may be implemented with many different materials, foam and clipcombinations with certain performance properties may be particularlywell suited when implemented for respiratory treatments given thecritical need to promote patient compliance and to ensure effectivedelivery of medical treatments. In this regard, particularly suitablecushion assemblies may be characterized by a spring constantcharacteristic.

In this regard, the spring rate of the cushion assemblies of the presenttechnology, which may be perceived as hardness of the cushion assembly,is more than just a sum of its parts. The parts (e.g., flexible clip andfoam cushion) work together to produce a final synergetic effect. Boththe foam and the underlying flexible clip can be tuned to each other.For example, if the characteristics of one changes, performance of thewhole assembly/system changes. Moreover, the spring rate characteristicsof the cushion and the clip assembly (e.g., cushion and flexible clip)can be different at set locations. The spring rate, also known as thespring constant or “k value”, may be the force produced per millimeterof deformation of a linear spring and may be determined by equationF=kX. For example, the spring rate may be determined by aligning a probeto act at a particular test location of the cushion/clip assembly, andmay be perpendicular to the surface of the frame. The probe may bedriven into the location (such as at 50 mm/min). The probe may bestopped when the force exceeds some limit (e.g., 10N). Theforce/displacement results may be recorded and graphed.

In relation to such a spring constant, example mask assemblies of thepresent technology are illustrated in the table below. These include aflexible clip +foam cushion assembly, denoted with FC and similar tothat of FIG. 47; another flexible clip +cushion assembly, denoted by FF,where the clip is being replaced with a contoured block of foamidentical to that of the cushion; a further flexible clip+cushionassembly (labelled as K1) is similar to assembly FF but has a sculptednasal recess, as illustrated in FIG. 69. These measurements werecomplimented by the measurements of other mask components, specifically,a flexible clip without foam SC, and a reference 25 mm thick foam slab,denoted in the table as “Foam”.

Spring constants were determined in various places of the cushionincluding bottom center, side of mouth region (points “corner 1” and“corner 2” are on the same side of the mouth with about a 0.5 cm offsetfrom each other in lateral direction), cheek bone region and threevertically aligned points along the nasal bridge region (points nasalbridge 1, nasal bridge 2 and nasal bridge 3 are offset with respect toeach other with about 0.5 cm in vertical direction). The spring constantdata in the table is summarized in Newtons per millimeter (N/mm). Thetable indicates for the (foam+clip) assembly with a sculpted nasalrecess, a greater spring constant in a mouth region (e.g., side of mouthregions) than in a nasal region (e.g., nasal bridge region) and similarspring constants in a nasal region and a cheek bone region. For theflexible clip only configuration (SC), the table indicates similarspring constants in a nasal region and the corners of the mouth region.It further illustrates a greater spring constant in a cheek region thana nasal region (e.g., nasal bridge region) but a lesser spring constantin a cheek region (e.g., cheek bone region) than a mouth region (e.g.,sides of mouth region).

The average numbers in the table are averaged over several samples. Eachof the minimum and the maximum numbers correspond to a singlemeasurement shown the smallest or the largest value for the particularlocation, respectively.

Bottom Corner 1 Corner 2 Cheek Bone Nasal Bridge 1 Nasal Bridge 2 NasalBridge 3 FC Average 0.11 0.09 0.07 0.07 0.11 0.09 0.08 FF Average 0.130.07 0.08 0.1 0.18 0.14 0.1 K1 Average 0.09 0.09 0.08 0.06 0.06 0.050.05 SC Average 0.12 0.74 0.77 0.26 0.13 0.09 0.07 Min SC 0.11 0.51 0.580.18 0.11 0.08 0.06 Max SC 0.13 0.88 1.04 0.32 0.15 0.1 0.07 Foam Min0.06 0.06 0.06 0.06 0.06 0.06 0.06 Foam Avera 0.13 0.13 0.13 0.13 0.130.13 0.13 Foam Max 0.18 0.18 0.18 0.18 0.18 0.18 0.18

5.5. Glossary

For the purposes of the present technology disclosure, in certain formsof the present technology, one or more of the following definitions mayapply. In other forms of the present technology, alternative definitionsmay apply.

5.5.1 General

Air: In certain forms of the present technology, air supplied to apatient may be atmospheric air, and in other forms of the presenttechnology atmospheric air may be supplemented with oxygen.

Continuous Positive Airway Pressure (CPAP): CPAP treatment will be takento mean the application of a supply of air or breathable gas to theentrance to the airways at a pressure that is continuously positive withrespect to atmosphere, and preferably approximately constant through arespiratory cycle of a patient. In some forms, the pressure at theentrance to the airways will vary by a few centimeters of water within asingle respiratory cycle, for example being higher during inhalation andlower during exhalation. In some forms, the pressure at the entrance tothe airways will be slightly higher during exhalation, and slightlylower during inhalation. In some forms, the pressure will vary betweendifferent respiratory cycles of the patient, for example being increasedin response to detection of indications of partial upper airwayobstruction, and decreased in the absence of indications of partialupper airway obstruction.

5.5.2 Anatomy of the Face

Ala: the external outer wall or “wing” of each nostril (plural: alar)

Alare: The most lateral point on the nasal ala.

Alar curvature (or alar crest) point: The most posterior point in thecurved base line of each ala, found in the crease formed by the union ofthe ala with the cheek.

Auricula or Pinna: The whole external visible part of the ear.

(nose) Bony framework: The bony framework of the nose comprises thenasal bones, the frontal process of the maxillae and the nasal part ofthe frontal bone.

(nose) Cartilaginous framework: The cartilaginous framework of the nosecomprises the septal, lateral, major and minor cartilages.

Columella: the strip of skin that separates the nares and which runsfrom the pronasale to the upper lip.

Columella angle: The angle between the line drawn through the midpointof the nostril aperture and a line drawn perpendicular to the Frankfurthorizontal while intersecting subnasale.

Frankfort horizontal plane: A line extending from the most inferiorpoint of the orbital margin to the left tragion. The tragion is thedeepest point in the notch superior to the tragus of the auricle.

Glabella: Located on the soft tissue, the most prominent point in themidsagittal plane of the forehead.

Lateral nasal cartilage: A generally triangular plate of cartilage. Itssuperior margin is attached to the nasal bone and frontal process of themaxilla, and its inferior margin is connected to the greater alarcartilage.

Greater alar cartilage: A plate of cartilage lying below the lateralnasal cartilage. It is curved around the anterior part of the naris. Itsposterior end is connected to the frontal process of the maxilla by atough fibrous membrane containing three or four minor cartilages of theala.

Nares (Nostrils): Approximately ellipsoidal apertures forming theentrance to the nasal cavity. The singular form of nares is naris(nostril). The nares are separated by the nasal septum.

Naso-labial sulcus or Naso-labial fold: The skin fold or groove thatruns from each side of the nose to the corners of the mouth, separatingthe cheeks from the upper lip.

Naso-labial angle: The angle between the columella and the upper lip,while intersecting subnasale.

Otobasion inferior: The lowest point of attachment of the auricle to theskin of the face.

Otobasion superior: The highest point of attachment of the auricle tothe skin of the face.

Pronasale: the most protruded point or tip of the nose, which can beidentified in lateral view of the rest of the portion of the head.

Philtrum: the midline groove that runs from lower border of the nasalseptum to the top of the lip in the upper lip region.

Pogonion: Located on the soft tissue, the most anterior midpoint of thechin.

Ridge (nasal): The nasal ridge is the midline prominence of the nose,extending from the Sellion to the Pronasale.

Sagittal plane: A vertical plane that passes from anterior (front) toposterior (rear) dividing the body into right and left halves.

Sellion: Located on the soft tissue, the most concave point overlyingthe area of the frontonasal suture.

Septal cartilage (nasal): The nasal septal cartilage forms part of theseptum and divides the front part of the nasal cavity.

Subalare: The point at the lower margin of the alar base, where the alarbase joins with the skin of the superior (upper) lip.

Subnasal point: Located on the soft tissue, the point at which thecolumella merges with the upper lip in the midsagittal plane.

Supramentale: The point of greatest concavity in the midline of thelower lip between labrale inferius and soft tissue pogonion.

5.5.3 Anatomy of the Skull

Frontal bone: The frontal bone includes a large vertical portion, thesquama frontalis, corresponding to the region known as the forehead.

Mandible: The mandible forms the lower jaw. The mental protuberance isthe bony protuberance of the jaw that forms the chin.

Maxilla: The maxilla forms the upper jaw and is located above themandible and below the orbits. The frontal process of the maxillaprojects upwards by the side of the nose, and forms part of its lateralboundary.

Nasal bones: The nasal bones are two small oblong bones, varying in sizeand form in different individuals; they are placed side by side at themiddle and upper part of the face, and form, by their junction, the“bridge” of the nose.

Nasion: The intersection of the frontal bone and the two nasal bones, adepressed area directly between the eyes and superior to the bridge ofthe nose.

Occipital bone: The occipital bone is situated at the back and lowerpart of the cranium. It includes an oval aperture, the foramen magnum,through which the cranial cavity communicates with the vertebral canal.The curved plate behind the foramen magnum is the squama

Orbit: The bony cavity in the skull to contain the eyeball.

Parietal bones: The parietal bones are the bones that, when joinedtogether, form the roof and sides of the cranium.

Temporal bones: The temporal bones are situated on the bases and sidesof the skull, and support that part of the face known as the temple.

Zygomatic bones: The face includes two zygomatic bones, located in theupper and lateral parts of the face and forming the prominence of thecheek.

5.5.4 Anatomy of the Respiratory System

Diaphragm: A sheet of muscle that extends across the bottom of the ribcage. The diaphragm separates the thoracic cavity, containing the heart,lungs and ribs, from the abdominal cavity. As the diaphragm contractsthe volume of the thoracic cavity increases and air is drawn into thelungs.

Larynx: The larynx, or voice box houses the vocal folds and connects theinferior part of the pharynx (hypopharynx) with the trachea.

Lungs: The organs of respiration in humans. The conducting zone of thelungs contains the trachea, the bronchi, the bronchioles, and theterminal bronchioles. The respiratory zone contains the respiratorybronchioles, the alveolar ducts, and the alveoli.

Nasal cavity: The nasal cavity (or nasal fossa) is a large air filledspace above and behind the nose in the middle of the face. The nasalcavity is divided in two by a vertical fin called the nasal septum. Onthe sides of the nasal cavity are three horizontal outgrowths callednasal conchae (singular “concha”) or turbinates. To the front of thenasal cavity is the nose, while the back blends, via the choanae, intothe nasopharynx.

Pharynx: The part of the throat situated immediately inferior to (below)the nasal cavity, and superior to the oesophagus and larynx. The pharynxis conventionally divided into three sections: the nasopharynx(epipharynx) (the nasal part of the pharynx), the oropharynx(mesopharynx) (the oral part of the pharynx), and the laryngopharynx(hypopharynx).

5.5.5 Materials

Silicone or Silicone Elastomer: A synthetic rubber. In thisspecification, a reference to silicone is a reference to liquid siliconerubber (LSR) or a compression moulded silicone rubber (CMSR). One formof commercially available LSR is SILASTIC (included in the range ofproducts sold under this trademark), manufactured by Dow Corning.Another manufacturer of LSR is Wacker. Unless otherwise specified to thecontrary, a preferred form of LSR has a Shore A (or Type A) indentationhardness in the range of about 35 to about 45 as measured using ASTMD2240

Polycarbonate: a typically transparent thermoplastic polymer ofBisphenol-A Carbonate.

5.5.6 Aspects of a Patient Interface

Anti-asphyxia valve (AAV): The component or sub-assembly of a masksystem that, by opening to atmosphere in a failsafe manner, reduces therisk of excessive CO₂ rebreathing by a patient.

Elbow: A conduit that directs an axis of flow of air to change directionthrough an angle. In one form, the angle may be approximately 90degrees. In another form, the angle may be less than 90 degrees. Theconduit may have an approximately circular cross-section. In anotherform the conduit may have an oval or rectangular cross-section.

Frame: Frame will be taken to mean a mask structure that bears the loadof tension between two or more points of connection with a headgear. Amask frame may be a non-airtight load bearing structure in the mask.However, some forms of mask frame may also be air-tight.

Headgear: Headgear will be taken to mean a form of positioning andstabilizing structure designed for use on a head. Preferably theheadgear comprises a collection of one or more struts, ties andstiffeners configured to locate and retain a patient interface inposition on a patient's face for delivery of respiratory therapy. Someties are formed of a soft, flexible, elastic material such as alaminated composite of foam and fabric.

Membrane: Membrane will be taken to mean a typically thin element thathas, preferably, substantially no resistance to bending, but hasresistance to being stretched.

Plenum chamber: a mask plenum chamber will be taken to a mean portion ofa patient interface having walls enclosing a volume of space, the volumehaving air therein pressurised above atmospheric pressure in use. Ashell may form part of the walls of a mask plenum chamber. In one form,a region of the patient's face forms one of the walls of the plenumchamber.

Seal: The noun form (“a seal”) will be taken to mean a structure orbarrier that intentionally resists the flow of air through the interfaceof two surfaces. The verb form (“to seal”) will be taken to mean toresist a flow of air.

Shell: A shell will preferably be taken to mean a curved structurehaving bending, tensile and compressive stiffness, for example, aportion of a mask that forms a curved structural wall of the mask.Preferably, compared to its overall dimensions it is relatively thin. Insome forms, a shell may be faceted. Preferably such walls are airtight,although in some forms they may not be airtight.

Stiffener: A stiffener will be taken to mean a structural componentdesigned to increase the bending resistance of another component in atleast one direction.

Strut: A strut will be taken to be a structural component designed toincrease the compression resistance of another component in at least onedirection.

Swivel: (noun) A subassembly of components configured to rotate about acommon axis, preferably independently, preferably under low torque. Inone form, the swivel may be constructed to rotate through an angle of atleast 360 degrees. In another form, the swivel may be constructed torotate through an angle less than 360 degrees. When used in the contextof an air delivery conduit, the sub-assembly of components preferablycomprises a matched pair of cylindrical conduits. Preferably there islittle or no leak flow of air from the swivel in use.

Tie: A tie will be taken to be a structural component designed to resisttension.

Vent: (noun) the structure that allows a deliberate controlled rate leakof air from an interior of the mask, or conduit to ambient air, to allowwashout of exhaled carbon dioxide (CO2) and supply of oxygen (O₂).

5.5.7 Terms Used in Relation to Patient Interface

Curvature (of a surface): A region of a surface having a saddle shape,which curves up in one direction and curves down in a differentdirection, will be said to have a negative curvature. A region of asurface having a dome shape, which curves the same way in two principledirections, will be said to have a positive curvature. A flat surfacewill be taken to have zero curvature.

Floppy: A quality of a material, structure or composite that is thecombination of features of:

Readily conforming to finger pressure.

Unable to retain its shape when caused to support its own weight.

Not rigid.

Able to be stretched or bent elastically with little effort.

The quality of being floppy may have an associated direction, hence aparticular material, structure or composite may be floppy in a firstdirection, but stiff or rigid in a second direction, for example asecond direction that is orthogonal to the first direction.

Resilient: Able to deform substantially elastically, and to releasesubstantially all of the energy upon unloading, within a relativelyshort period of time such as 1 second.

Rigid: Not readily deforming to finger pressure, and/or the tensions orloads typically encountered when setting up and maintaining a patientinterface in sealing relationship with an entrance to a patient'sairways.

Semi-rigid: means being sufficiently rigid to not substantially distortunder the effects of mechanical forces typically applied during positiveairway pressure therapy.

5.6 Other Remarks

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

Unless the context clearly dictates otherwise and where a range ofvalues is provided, it is understood that each intervening value, to thetenth of the unit of the lower limit, between the upper and lower limitof that range, and any other stated or intervening value in that statedrange is encompassed within the technology. The upper and lower limitsof these intervening ranges, which may be independently included in theintervening ranges, are also encompassed within the technology, subjectto any specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either orboth of those included limits are also included in the technology.

Furthermore, where a value or values are stated herein as beingimplemented as part of the technology, it is understood that such valuesmay be approximated, unless otherwise stated, and such values may beutilized to any suitable significant digit to the extent that apractical technical implementation may permit or require it.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this technology belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present technology, a limitednumber of the exemplary methods and materials are described herein.

When a particular material is identified as being preferably used toconstruct a component, obvious alternative materials with similarproperties may be used as a substitute.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include their plural equivalents,unless the context clearly dictates otherwise.

All publications mentioned herein are incorporated by reference todisclose and describe the methods and/or materials which are the subjectof those publications. The publications discussed herein are providedsolely for their disclosure prior to the filing date of the presentapplication. Nothing herein is to be construed as an admission that thepresent technology is not entitled to antedate such publication byvirtue of prior invention. Further, the dates of publication providedmay be different from the actual publication dates, which may need to beindependently confirmed.

Moreover, in interpreting the disclosure, all terms should beinterpreted in the broadest reasonable manner consistent with thecontext. In particular, the terms “comprises” and “comprising” should beinterpreted as referring to elements, components, or steps in anon-exclusive manner, indicating that the referenced elements,components, or steps may be present, or utilized, or combined with otherelements, components, or steps that are not expressly referenced.

The expressions “soft” and “flexible”, as well as their derivatives,when used in this specification to describe the first support clip 3812(FIG. 40), are intended to have the meaning of the expression“resilient” as specifically defined in section “Terms used in relationto patient interface”. This is to say, the flexible supporting clip isable to deform substantially elastically, and to quickly releasesubstantially all of the energy upon unloading.

The subject headings used in the detailed description are included onlyfor the ease of reference of the reader and should not be used to limitthe subject matter found throughout the disclosure or the claims. Thesubject headings should not be used in construing the scope of theclaims or the claim limitations.

Although the technology herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thetechnology. In some instances, the terminology and symbols may implyspecific details that are not required to practice the technology. Forexample, although the terms “first” and “second” may be used, unlessotherwise specified, they are not intended to indicate any order but maybe utilised to distinguish between distinct elements. Furthermore,although process steps in the methodologies may be described orillustrated in an order, such an ordering is not required. Those skilledin the art will recognize that such ordering may be modified and/oraspects thereof may be conducted concurrently or even synchronously.

It is therefore to be understood that numerous modifications may be madeto the illustrative embodiments and that other arrangements may bedevised without departing from the spirit and scope of the technology.

5.7 PARTS LIST

-   patient 1000-   partner 1100-   patient interface 3000-   seal forming structure 3100-   cushion 3110-   nasal ridge 3131-   plenum chamber 3200-   positioning and stabilising structure 3300-   vent 3400-   frame 3500-   decoupling structure 3510-   flange 3515-   clip 3535-   concave wall 3535W-   connector 3536-   fastener 3537-   cushion support surface 3538-   frame coupling surface 3539-   peripheral lip 3540-   middle transverse portion 3541-   extra cantilever protrusion 3561-   bulbous ridge 3572-   channel 3574-   finger 3576-   skirt 3578-   snap shoulder 3580-   engagement cavity 3582-   exploded view 3583-   peripheral channel 3585-   taper element 3586-   taper receiving channel 3587-   connection port 3600-   forehead support 3700-   peripheral rim 3702-   scalloped notch 3763-   protrusion 3764-   anti-asphyxia valve 3800-   foam cushion 3810-   first clip 3812-   projection 3813-   second clip 3814-   mask frame 3816-   ports 3900-   foam cushion assembly 3901-   pap device 4000-   external housing 4010-   upper portion 4012-   lower portion 4014-   panel 4015-   chassi 4016-   handle 4018-   pneumatic block 4020-   pneumatic block 4020-   coupling ridge 4022-   snap element 4024-   ridge stop 4025-   taper 4027-   pneumatic component 4100-   inlet air filter 4112-   inlet muffler 4122-   outlet muffler 4124-   controllable source 4140-   blower 4142-   air/gas circuit4170-   electrical component 4200-   PCBA 4202-   electrical power supply 4210-   input device 4220-   pressure sensor 4272-   flow sensor 4274-   therapy engine module 4320-   coupling portion 4840-   support portion 4842-   base portion 4844-   location ridge 4845-   cushion coupling portion 4848-   humidifier 5000-   lip seal 5550-   flexible lip seal 5550-   hard stop 5551-   rigid clip 5858-   shell 6160-   headgear frame 6162-   shell aperture 6163-   rigid clip 6314-   engagement feature 6319-   flexible member 6320-   clip 6470-   clip portion 6580-   slit 6582-   rigid clip 6758-   clip recess 6770-   recess membrane 6772-   point 6910A-   point 6910B-   width 6910C-   nasal recess 6912-   location 7310H-   edge 7660-   rigid mask frame portion 7662-   engagement rib 7664-   engagement groove 7666-   point 7668-   frame opening 8012-   receiving slot 8014-   cushion support structure 8800

1. A foam cushion assembly for a patient respiratory interface, the foamcushion assembly comprising: a foam cushion for sealing about at least anose of a user, and a flexible support component attached to a surfaceof the foam cushion for supporting the foam cushion, wherein the foamcushion has an air permeability characteristic in a range of 0 to 20litters per minute.
 2. The foam cushion assembly of claim 1 wherein thefoam cushion has an indentation hardness characteristic in a range of110.48 to 303.11 Newtons.
 3. The foam cushion assembly of claim 1wherein the foam cushion has an apparent density characteristic in arange of 24.3 to 117.85 kilograms per meter cubed.
 4. The foam cushionassembly of claim 1 wherein the foam cushion has a dynamic coefficientof friction characteristic in a range of about 2.43 to 2.97 CF.
 5. Thefoam cushion assembly of claim 1 wherein the foam cushion has acompression stress strain characteristic in a range of 2.32 to 7.26kilo-pascals.
 6. The foam cushion assembly of claim 1 wherein the foamcushion has any one or more of: (a) a compression set characteristic ina range of 0.16 to 17.30 percent, (b) a tensile strength characteristicin a range of about 0.117 to 0.143 Mpa, (c) an elongation at breakcharacteristic in a range of about 243 to 335.5%, and (d) a tearstrength characteristic in a range of about 0.225 to 0.297 N/mm.
 7. Thefoam cushion assembly of claim 1, wherein the foam cushion and flexiblesupport component form a combined assembly that has a spring ratecharacteristic in a range of 0.05 to 0.11 Newtons per millimeter.
 8. Thefoam cushion assembly of claim 1 wherein the foam cushion and theflexible support component form a combined assembly that has a mouthregion and a nasal region, and wherein a spring rate characteristic ofthe combined assembly in the mouth region is greater than a spring ratecharacteristic of the combined assembly in the nasal region.
 9. The foamcushion assembly of claim 8 wherein the combined assembly has a cheekregion and wherein the spring rate characteristic of the combinedassembly in the mouth region is greater than a spring ratecharacteristic of the combined assembly in the cheek region.
 10. Thefoam cushion assembly of claim 9 wherein the spring rate characteristicof the combined assembly in the cheek region is equivalent to the springrate characteristic of the combined assembly in the nasal region. 11.The foam cushion assembly of claim 10 wherein the flexible supportcomponent has a spring rate characteristic in the cheek region that isgreater than a spring rate characteristic of the flexible supportcomponent in the nasal region.
 12. The foam cushion assembly of claim 11wherein the flexible support component has a spring rate characteristicin the mouth region that is greater than the spring rate characteristicof the flexible support component in the cheek region.
 13. The foamcushion assembly of claim 1, wherein the foam cushion and the flexiblesupport component are adapted to form a nasal only mask.
 14. A maskapparatus for a respiratory treatment comprising: the foam cushionassembly of claim 1; and a frame adapted to couple with a respiratorytreatment apparatus so as to permit communication of a pressurized gasto a respiratory system of a patient from the respiratory treatmentapparatus; and wherein the frame is adapted to couple with the foamcushion assembly.
 15. The mask apparatus of claim 14, wherein the foamcushion is configured as a substantially under nose seal portion, theunder nose seal portion comprising a sub-nasal ridge formed as asemi-peripheral sealing boundary about both nares of the patient. 16.The mask apparatus of claim 15 wherein the foam cushion comprises atriangular ring having a common nasal and mouth aperture.
 17. The maskapparatus of claim 15 wherein the foam cushion and the frame form acommon plenum chamber for sealing about the nares and mouth.
 18. Themask apparatus of claim 15, wherein the sub-nasal ridge includes ascalloped edge.
 19. The mask apparatus of claim 14, wherein the foamcushion comprises a protrusion configured to ply adjacent to a nasal alaof the patient.
 20. The mask apparatus of claim 14, wherein the foamcushion comprises left and right nasal ala protrusions.
 21. The maskapparatus of claim 14, wherein the flexible support component comprisesfirst and second opposing sides, and wherein the flexible supportcomponent is configured to couple with the foam cushion on the firstopposing side and to couple with the frame on the second opposing side.22. The mask apparatus of claim 14, wherein the flexible supportcomponent comprises a nasal plateau region and a mouth periphery region.23. The mask apparatus of claim 22 wherein the nasal plateau region isapproximately perpendicular to the mouth periphery region.
 24. The maskapparatus of claim 22 wherein the flexible support component comprises abend region between the nasal plateau region and the mouth peripheryregion, the bend region forming an approximately nasolabial anglebetween the nasal plateau region and the mouth periphery region.
 25. Themask apparatus of claim 24 wherein the bend region comprises a set ofinwardly directing nasal protrusions.
 26. The mask apparatus of claim 25wherein the nasal protrusions are flexible.
 27. The mask apparatus ofclaim 14, wherein the flexible support component comprises first andsecond cushion support portions, the first and second cushion supportportions being configured to provide different flexibilitycharacteristics.
 28. The mask apparatus of claim 27 wherein the firstcushion support portion comprises a nasal support region and the secondcushion support portion comprises a lateral mouth support region, thefirst cushion support portion having a higher rigidity characteristicwith respect to the second cushion support portion.
 29. The maskapparatus of claim 14, wherein the foam cushion comprises a generallyflat sealing surface.
 30. The mask apparatus of claim 14, wherein thefoam cushion comprises a generally curved sealing surface.
 31. The maskapparatus of claim 14, further comprising the respiratory treatmentapparatus configured to generate a controlled supply of a breathable gasat a pressure above atmospheric pressure, the respiratory treatmentapparatus including a gas delivery conduit coupled with the frame todirect the breathable gas to the frame.
 32. The mask apparatus of claim14, wherein the flexible support component is inwardly concave.
 33. Themask apparatus of claim 14, wherein the flexible support component ismade of a material other than foam.
 34. The mask apparatus of claim 14,wherein the foam cushion is externally attached to the flexible supportcomponent.
 35. The mask apparatus of claim 14, wherein a foam surface ofthe foam cushion is configured for direct contact with skin of apatient.
 36. The mask apparatus of claim 14, wherein foam of the foamcushion is a semi-open cell foam with limited permeability.
 37. The maskapparatus of claim 14, wherein the foam cushion further defines acentrally open lip superior region.
 38. The mask apparatus of claim 37wherein the foam cushion comprises a nasal plateau region and a mouthperiphery region, the foam cushion configured with an approximatelynasolabial angle between the nasal plateau region and the mouthperiphery region.
 39. The mask apparatus of claim 37, wherein the foamcushion and the frame form a common plenum chamber for sealing about auser's nares and mouth, wherein the centrally open lip superior regionis within the common plenum chamber.
 40. The mask apparatus of claim 14,wherein the flexible support component comprises flexible nasalprotrusions.
 41. The mask apparatus of claim 14, wherein the foamcushion is further configured with a mouth seal portion.